相关习题
 0  89493  89501  89507  89511  89517  89519  89523  89529  89531  89537  89543  89547  89549  89553  89559  89561  89567  89571  89573  89577  89579  89583  89585  89587  89588  89589  89591  89592  89593  89595  89597  89601  89603  89607  89609  89613  89619  89621  89627  89631  89633  89637  89643  89649  89651  89657  89661  89663  89669  89673  89679  89687  151629 

科目: 来源: 题型:阅读理解

While learning the science lessons,I used to get a doubt—why ear,nose,tongue and eyes should be called as special senses?The basic reason is that these are the channels through which we maintain contact with the surroundings.Though apparently it may feel like these are individual sensory organs,they do show some connectivity.Interestingly,our hearing is less sharp after we eat a heavy food.Isn’t it good for a sound nap after a stomach­full meal?That does not mean we go deaf after a meal,but the hearing pitch(强度) does change after a heavy meal.
We usually give credit of the taste to our tongue,but do you know that unless saliva(唾液) dissolves something,our tongue cannot recognize the taste of the food eaten.Taste is nothing but the food chemicals dissolved in the saliva being sensed by the taste buds present on the tongue.Try_to_dry_off_your_tongue_and_mouth_with_a_tissue_paper_and_then_taste_something.
Women are much better smellers than men.They are born with this characteristic ability and can correctly pinpoint the exact fragrance of the sample.We all can store almost 50,000 different scents(气味),which are strongly tied to the memories.
Pupils(瞳孔) do not respond to light alone,but to the slightest bit of noise around too.Thus surgeons,watchmakers and those professionals who have to perform a much delicate job do prefer to have a sound­free environment.Even a small noise can dilate(扩大) their pupils,change the focus and blur(使模糊) their vision.If you do not wear glasses or contact lens due to having a 6/6 vision,you are just among the one third of the human population.It is now statistically proved that only one third of the population has perfect vision,rest all are either wearing glasses or are trying to read with a compromised vision.
Each and every one of us has a particular or individualistic or characteristic smell,which is unique to us,except for the identical twins.This smell is very subtle(微妙的) yet can be sensed even by a newborn.It may be due to this scent that the newborn recognizes the presence of his parents around.Many of us can pinpoint the smell of our significant friends and colleagues.A significant part of this phenomenon is guided by genetics but it is also modified by the environment,diet and personal hygiene.This all together creates the unique chemistry that is individualistic for each person.
【小题1】We can learn from Paragraph 1 that ________.

A.after a full meal our hearing is as good as before
B.all sensory organs are connected and can be exchanged
C.sensory organs’ functions can never be changed for their particular character
D.we feel and learn about the world around us through our eyes,ears,nose and tongue
【小题2】What is the text mainly about?
A.The functions of sensory organs.
B.The connectivity of sensory organs.
C.A newborn’s senses of the sensory organs.
D.The differences of senses between women and men.
【小题3】What does the author mean by the underlined sentence in Paragraph 2?
A.Our tongues can’t be dried while eating something.
B.If your tongue is dried without any saliva on it,it will not work.
C.A tissue paper is the only thing that can be used to dry our tongues.
D.If your tongue is dried with a tissue paper,it may work as well as before.

查看答案和解析>>

科目: 来源: 题型:阅读理解

Founded in 1966,Seacamp,the first program dedicated to the education of youth in marine(海洋的) sciences,is the result of a cooperative effort of parents,scientists,businessmen and camp leaders.Preservation practices and a respect for the marine environment are the philosophy of the Seacamp.
Seacamp’s tropical marine location in the lower Florida Keys enables it to offer a truly unique marine science program.This program is the heart of Seacamp.Young scientists participate in a variety of courses under the guidance of academically trained marine science instructors and biologists.All science activities include studies in both the field and the laboratory.Each session,140 to 160 campers come to Seacamp,mostly from the US,but also from across the world.There are about 30 international campers each summer from an average of twelve countries.Many Seacamp program graduates have gone on to careers as environmental educators and marine scientists.
One of Seacamp’s unique aspects is that campers create their schedules.In addition to science classes,campers choose from a variety of programs to ensure that there is something interesting and exciting for everyone.Campers interested in journalism may work on the camp newspaper,SEASCOPE,which is published periodically during camp sessions.Arts activities are also included.Photography allows campers to take home memories of friends,wildlife,and underwater experiences.
Seacamp teaches the fun and skills of sailing.It’s an excellent way for future marine scientists to become familiar with the winds,tides and currents that are of primary concern in oceanography.Basic Red Cross certification is offered to beginners in sailing.The Red Cross course in advanced lifesaving is taught at Seacamp.The course is designed to increase the campers’ ability to recognize and avoid dangerous water conditions and practices and to use self­rescue skills to get out of dangerous situations.
Parents may bring campers by car to Big Pine Key.Counselors(辅导员) also meet participants at the Miami International Airport on the opening day of camp and accompany them to Big Pine Key on a bus.The fee for round­trip service is $90.To join the Seacamp adventure,interested campers should contact Seacamp for an application.
We love to talk about camp!For more information or to ask any questions you might have,please give our friendly staff a call and we’ll be glad to help!
【小题1】According to the text,Seacamp is designed to help campers ________.

A.have a good time at the seaside
B.develop a sense of marine protection
C.make a further study about sea life
D.complete a course about marine wildlife
【小题2】It can be learned from Paragraph 3 and 4 that ________.
A.Seacamp offers many programs apart from science classes
B.Seacamp is responsible for training marine scientists
C.beginners in sailing should learn the advanced Red Cross course
D.Seacamp provides traditional camp activities such as arts and crafts
【小题3】The main purpose of the text is to ________.
A.attract the young to Seacamp
B.present Seacampers’ experiences
C.introduce the programs of Seacamp
D.explain the aim of Seacamp

查看答案和解析>>

科目: 来源: 题型:阅读理解

When author Nicholas Carr began researching his book on whether the Internet is ruining our minds,he restricted his online access and e­mail.His new book argues the latest technology renders us less capable of deep thinking.Carr found himself so distracted(分心的) that he couldn’t work on the book while staying as connected.After first feeling confused by his sudden lack of online connection,he was able to stay focused on one task for a long period within several weeks.
Reading on the Internet has changed how we use our brains.Facing a lot of texts,video,music and links to other web pages and blogs,our minds have become used to skimming and scanning information.As a result,we have developed sharper skills at making fast decisions,particularly visual ones,Carr wrote.
But now most of us seldom read books or long articles that would help us focus.We are becoming more like librarians—able to find information quickly and see clearly the best nuggets(有价值的资料).That lack of focus hinders(阻碍) our long­term memory,leading many of us to feel distracted,he wrote.
“What we are losing is a whole other set of mental skills,which require not the shifting of our focus but the maintaining of our focus,” Carr said,adding that for centuries books protected our brains from distraction and focused our minds on one topic at a time.
But with devices such as Apple’s iPad becoming common,Carr predicts books also will change.“New forms of reading always require new forms of writing,” he said.Carr has a suggestion for those who feel web surfing has left them incapable of concentration—slow down,turn off the Internet and practice the skills of contemplation(沉思) and reflection.“It is pretty clear from the brain science that if you don’t exercise particular cognitive skills,you are going to lose them,” he said.“If you are constantly distracted,you are not going to think in the same way that you would think if you paid attention.”
【小题1】What topic is Nicholas Carr’s new book mainly concentrating on?

A.Whether there is any need for us to surf the Internet.
B.How the Internet changes our way of thinking.
C.What we should do when we are surfing the Internet.
D.Whether our minds are being influenced by the Internet.
【小题2】How did Nicholas Carr feel after he limited his time online several weeks later?
A.Anxious.B.Relaxed.
C.Concentrated.D.Puzzled.
【小题3】The underlined word renders in Paragraph 1 probably means ________.
A.preventsB.causes
C.protectsD.sharpens
【小题4】What’s Nicholas Carr’s suggestion for people who are often distracted by the Internet?
A.They should read more books besides surfing the Internet.
B.They should often slow down their pace of modern living.
C.They should often get away from the disturbing of the Internet.
D.They should spend more time thinking while surfing the Internet.

查看答案和解析>>

科目: 来源: 题型:阅读理解

Life in space will certainly take some getting used to!But the space station has been designed to keep the astronauts as comfortable as possible—the modules(舱) are roomy,bright,and kept at a constant 70 degrees Fahrenheit.It’s important the crew members are comfortable because they’ll be busy aboard the station.In a typical workday,crew members will spend 14 hours working and exercising,1.5 hours preparing and eating meals,and 8.5 hours sleeping.Here are some other fun facts about life aboard the station:
Food
Come mealtime,astronauts will have a special dining kitchen.Space food just keeps getting better—and more like food we enjoy here on Earth.In early space missions,astronauts could eat only freeze­dried food that didn’t require any preparation.But the space station is equipped with water,microwave ovens,and refrigerators,allowing the folks on board to eat more “normal” types of food,including fruit,vegetables,and ice cream!
Sleep
Each crew member has a private room.With no gravity,they’ll need to tie themselves to their beds,or they will float away!That might sound like a strange way to sleep,but astronauts from past space missions report that sleeping in space is actually pretty great!
Exercise
You might not think it,but exercise is even more important on the station than it is on Earth.There is not much gravity in space.Astronauts don’t stand up,sit down or walk in space,so their muscles and bones don’t have to work much—and this muscle and bone loss can be dangerous back on Earth.To fight this,astronauts on the station will exercise on bikes,rowing machines,and other equipment about two hours every day.
Clothing
Astronauts will have to wear special space suits while traveling aboard the U.S.shuttle or Russian rockets.But once they’re safe inside the space station,crew members can wear regular clothing.Of course,a specially designed,pressurized space suit is required for space walks.It has to withstand(经受住) flying pieces and protect the astronauts from dramatic temperature changes.It can range from 120 degrees below Fahrenheit in the shadow of the station to 250 degrees in the hot sun.
Personal Cleanliness
Simple tasks like brushing your teeth can be challenging in a weightless environment.A little water doesn’t flow in a stream—it suspends in a bubble!Astronauts will use a freshwater hose(软管) to take showers,shampoo,and wash off—then a second vacuum hose to suction(吸) off the dirty water.And how do you go to the bathroom in space?With a special “air toilet” that uses flowing air instead of water to dispose of waste.
【小题1】The facts about life in space are all mentioned EXCEPT ________.

A.clothing B.entertainment
C.sleep D.exercise
【小题2】What can be learned from the paragraph “Clothing”?
A.The temperature is quite different in different places in space.
B.Astronauts must wear special space suits all the time in space.
C.Astronauts can wear regular clothing for space walks now.
D.Astronauts wear pressurized space suits just to keep warm.
【小题3】Why is exercise more important in space than on earth?
A.It can make astronauts feel relaxed in space.
B.It can help astronauts spend their spare time happily.
C.Astronauts’ lives are more important in space than on earth.
D.It can prevent astronauts from causing muscle and bone loss.
【小题4】What do we know about space food from the text?
A.Astronauts could eat apples in space in the past.
B.Astronauts eat only fruit,vegetables and ice cream now.
C.Fresh food isn’t available to astronauts in space.
D.Space food is getting better now than before.

查看答案和解析>>

科目: 来源: 题型:阅读理解

According to body language expert Robert Phipps,the way people sleep at night actually determines a lot about the type of personality they have.Phipps has identified four sleeping positions that affect personality.
Phipps found that worriers,those who stress the most,tend to sleep in the fetal(胎儿的)position.He found that this is the most common bedtime position,with nearly 58 percent of people sleeping on their side with knees up and head down.The more we curl up(蜷曲),the more comfort we are seeking,according to Phipps.
The second most common position is the log.Sleeping with a straight body,with arms at each side,as if they are standing guard at Buckingham Palace,indicates stubbornness,and these people(the 28 percent who sleep this way)often wake up stiffer than when they went to sleep.
“The longer you sleep like this,the more rigid your thinking is and you can become inflexible,which means you make things harder for yourself,”according to Phipps.
Yearner(向往型)sleepers are next on the list.About 25 percent of people sleep in this style—on their side with arms stretched out in front,looking as if they are either chasing a dream or perhaps being chased themselves.Yearners are typically their own worst critics,always expecting the best results,explained Phipps.These people often wake up refreshed and eager to face the challenges of the day ahead.
Perhaps the most peculiar(奇怪的)of sleep styles is the freefaller position.This sleep style makes up 17 percent of the population.They sleep face down with arms stretched out.These people,according to Phipps,feel like they have little control over their life.Not only is this the strangest of sleep styles,but also the least comfortable,and people may wake up feeling tired and have no energy.
In conclusion,Phipps has only one more thing to add:“A good night's sleep sets you up for the following day and our sleeping positions can determine how we feel when we wake.”
【小题1】Which of the following is the best title of the passage?

A.A Good Night's Sleep Sets You Up for the Following Day
B.Your Personality Depends a Lot on How You Sleep at Night
C.How You Sleep at Night Affects What You Do the Next Day
D.Which Sleeping Position Helps You Sleep Comfortably
【小题2】Which of the following pictures is the fetal position?

【小题3】The underlined word“rigid”is closest in meaning to “________”.
A.stubbornB.flexible
C.comfortableD.strange
【小题4】Which of the following shows the structure of the passage?
CP:Central  P:Point Sp:Sub?point
C:Conclusion

查看答案和解析>>

科目: 来源: 题型:阅读理解

Many people think of the brain as a mystery.They don't know much about intelligence and how it works.When they do think about what intelligence is,many people believe that a person is born smart,average,or dumb—and stays that way in the whole life.But new research shows that the brain is more like a muscle—it changes and gets stronger when you use it.And scientists have been able to show just how the brain grows and gets stronger when you learn.
Everyone knows that when you lift weights,your muscles get bigger and you get stronger.A person who can't lift 20 pounds when he/she starts exercising can get strong enough to lift 100 pounds after working out for a long time.That's because the muscles become larger and stronger with exercise.And when you stop exercising,the muscles shrink and you get weaker.That's why people say “Use it or lose it!”
But most people don't know that when they practice and learn new things,parts of their brain change and get larger a lot like muscles do when they exercise. Inside the cortex(皮层)of the brain are billions of tiny nerve cells,called neurons. The nerve cells have branches connecting them to other cells in a complicated network. Communication between these brain cells is what allows us to think and solve problems. When you learn new things,these tiny connections in the brain actually multiply and get stronger.The more you challenge your mind to learn,the more your brain cells grow.Then,things that you once found very hard or even impossible to do—like speaking a foreign language or doing algebra(代数)—seem to become easy after learning them for a period of time.The result is a stronger,smarter brain.
Scientists started thinking that the human brain could develop and change when they studied animals'brains.They found out that animals that lived in a challenging environment were more perspicacious—they were better at solving problems and learning new things.
【小题1】According to the first paragraph,________.

A.the function of our brain is like that of the muscle
B.until now it's impossible to explain the brain's mystery
C.many people believe one's intelligence is naturally determined
D.one's brain grows stronger as the age increases
【小题2】Training muscles is compared to ________.
A.using the brain
B.connecting things in your brain
C.lifting weights
D.doing research about the brain
【小题3】What does the underlined word“perspicacious”in the last paragraph probably mean?
A.Strong. B.Smart.
C.Popular. D.Active.
【小题4】The following paragraph will most probably talk about ________.
A.the differences between animals'brains and humans'brains
B.the relation between human brains and muscles
C.scientists' findings about animals' brains
D.how to make your brain smarter through self?development

查看答案和解析>>

科目: 来源: 题型:阅读理解

Even while in a deep sleep, people can still learn brand new information. Sleepers soak in new associations between smells and sounds, knowledge that lingers(逗留)into the next waking day, researchers report online August 26 in Nature Neuroscience.
The new study is the first to show that entirely new information can get into the sleeping mind, says Anat Arzi of the Weizmann Institute of Science in Israel. "The brain is not passive while you sleep. It's quite active. You can do quite a lot of things while you are asleep."
But the results don't mean that Spanish vocabulary tapes now have a place on the nightstand. L, Researchers have tried but largely failed to find evidence that complicated information, such as new pairs of words, can make its way into the brain during sleep.
Instead of trying to teach people something complicated like a new language, Arzi and her colleagues relied on the sense of smell and hearing. As anyone who has walked by a dumpster(垃圾车)in July knows, smells can cause a nose-jerk reaction. Catching a bad smell automatically makes people inhale(吸气)less, reducing the size of the inhale. But scent of fresh bread causes a long, deep inhale.、rzi and her team took advantage of this reaction for their experiment.
As people slept in the laboratory, the researchers delivered pleasant scent, such as shampoo. As this nice smell got into the sleepers' noses, the researchers played a particular music. Later, a disgusting smell, such as rotten fish or meat, was paired with a different music. Neither the smell nor the sound woke people up. After just four exposures to the smell-music pair during a single night, the sleepers started to automatically respond to the tones without the accompanying smells, taking in bigger breaths when the shampoo-associated tone played and smaller breaths when played the sound linked to the rotten fish smell.
This new learned association lingered into the next waking day, too. Even though the sleepers had no idea they had been exposed to smells or sounds, their behavior proved that their brain had actually learned something during sleep. As before, the shampoo sound stimulated a long, deep inhale, while the rotten fish tone caused more shallow breaths.
【小题1】We can infer from the passage that

A.while sleeping, we can learn whatever we want to learn
B.we will increase the size of inhale if we catch a pleasant smell
C.the knowledge we learned while sleeping will be forgotten in the next waken day
D.when walking by a bakery, the fresh bread will cause a nose-jerk reaction
【小题2】What is Paragraph 3 mainly about?
A.One can’t acquire complicated knowledge during the sleeping hours.
B.Spanish vocabulary tapes now have a place on the nightstand
C.Researchers have tried to find evidence that the new words can be learned during sleep.
D.Complicated information can make its way into the brain during sleep
【小题3】How do Arzi and her team do their research? By
A.giving instructions B.analyzing human brains
C.following the guides of others D.doing experiments
【小题4】In which part of a website may this passage most likely appear?
A.Culture. B.Science. C.History. D.Economy.

查看答案和解析>>

科目: 来源: 题型:阅读理解

Rising levels of carbon dioxide in the atmosphere are a major cause of climate change, and now a new study has confirmed that atmospheric CO2 is also affecting the ocean chemistry and potentially harming sea life.
Montana State University scientist Robert Dore has been researching the water in the Pacific Ocean for almost two decades. "We've been going to the same spot in the Pacific Ocean, and we try and characterize long-term change in the open ocean environment. And one of the key things that we measure is COx levels. And We've been able to record this increasing quantity of atmospheric CO, into the ocean. "Scientists expected that as atmospheric CO2 increased, more and一 more of the carbon dioxide would be absorbed into the ocean, affecting the chemical balance of the sea water, with a potentially harmful impact on shellfish and coral in particular.
"As carbon dioxide dissolves in the water, or seawater in this case, it forms a weak acid, carbonic acid," Dore explains. "And therefore, as the concentration of CO2 in the atmosphere goes up and that exchanges with the surface seawater, it drives the pH down, and makes it more acidic."
The seawater samples Dow and his colleagues have analyzed confirm what the theory predicts. The effect was particular striking at about 250 meters down, and again at 500 meters. Dore and his colleagues came up with two possible explanations. It could be that surface water picked up CO2 and then moved to those depths. Or there could be a biological explanation.
"It's important to realize that the oceans are really becoming acidic. And it can have negative impacts on a whole variety of sea life from fish to coral. It’s potentially catastrophic."
【小题1】What can be the best title of the passage?

A.Sea Life Facing DangerB.Scientist Researching Seawater
C.Oceans Becoming More AcidicD.Climate Change Affecting Seawater
【小题2】With the increase of atmospheric C02,_.
A.more corals will appear in the sea
B.the surface water is becoming warmer
C.the chemical balance of the seawater is affected
D.the pH of the ocean out here has been increasing
【小题3】Which of the following shows the process of the impact of atmospheric C02 on sea life?
a. Sea life is endangered. b. C02 goes into the surface water.
c. The ocean chemistry is affected. d. C02 levels in the atmosphere go up
e. C02 decreases the pH and makes the seawater more acidic.
A.abcdeB.dbceaC.aebedD.edcba
【小题4】Scientist Robert Dore came to the conclusion based on_.
A.his research and analysisB.the expectation of other scientists
C.some former theoryD.a major cause of climate change

查看答案和解析>>

科目: 来源: 题型:阅读理解

Most people are aware that outdoor air pollution can damage their health,but many do not know that indoor air pollution can also have significant health effects.Environmental Protection Agency studies indicate that indoor levels of pollutants may be 3~5 times,and occasionally more than 100 times,higher than outdoor levels.These levels of indoor air pollutants may be of particular concern because most people spend about 90% of their time indoors.
There are many sources of indoor air pollution in any home.These include sources such as oil,gas,coal,wood,and tobacco products,building materials,wet or damp carpet,and furniture made of certain pressed wood products,products for household cleaning and maintenance,personal care,or hobbies,central heating and cooling systems.
Immediate effects may show up after a single exposure (暴露) or repeated exposures.These include irritation of the eyes,nose,and throat,headaches,dizziness.Such immediate effects are usually short­term and treatable.Sometimes the treatment is simply removing the person’s exposure to the source of the pollution,if it can be identified.
The likelihood of immediate reactions to indoor air pollutants depends on several factors.Age and pre­existing medical conditions are two important influences.In other cases,whether a person reacts to a pollutant depends on individual sensitivity,which varies tremendously from person to person.Some people can become sensitized to biological pollutants after repeated exposures,and it appears that some people can become sensitized to chemical pollutants as well.
Certain immediate effects are similar to those from colds or other viral (病毒性的) diseases,so it is often difficult to determine if the symptoms are a result of exposure to indoor air pollution.While pollutants commonly found in indoor air are responsible for many harmful effects,there is considerable uncertainty about what concentrations or periods of exposure are necessary to produce specific health problems.People also react very differently to exposure to indoor air pollutants.Therefore,further research is needed to better understand the effects of indoor air pollution and to find efficient ways to protect our health.
【小题1】According to the first paragraph,which of the following is NOT true?

A.People often fail to notice indoor air pollution.
B.Indoor air pollution sometimes is more dangerous than outdoor air pollution.
C.Outdoor air pollution may not be so serious as indoor air pollution.
D.It is obvious that people have been paying more attention to indoor air pollution.
【小题2】According to the author,which may NOT be the source of indoor air pollution?
A.Building materials. B.Wet carpet.
C.Cooling system. D.Refrigerators.
【小题3】What does the underlined word “irritation” in the third paragraph probably mean?
A.Bad intention. B.Much sensitivity.
C.Injury. D.Carelessness.
【小题4】Which of the following might be the best title for the passage?
A.Reactions of Pollution B.Danger from Home
C.Pollution Resources D.Different Pollutions

查看答案和解析>>

科目: 来源: 题型:阅读理解

Scientists in Israel have discovered a new way to test for water pollution by “listening” to what the plants growing in water have to say.
By shining a laser beam (激光束) on the tiny pieces of algae floating in the water,the researchers said they hear sound waves that tell them the type and amount of contamination (致污物) in the water.
“It is a red light,telling us that something is beginning to go wrong with the quality of water,” said Zvy Dubinsky,an aquatic biologist at Israel’s Bar Ilan University.“Algae is the first thing to be affected by a change in water quality.”“The secret,” he said,“is to measure the rate of photosynthesis (光合作用) in the algae,meaning the plant’s ability to transform light into energy.” During photosynthesis,plants also release oxygen into the air.
Dubinsky’s technique is easy to perform because of the over­abundance of algae in the planet’s water.Most of the oxygen in the atmosphere comes from algae.A prototype tester that occupies about one square meter of a laboratory desktop,shoots a laser beam at water samples to stimulate photosynthesis in the algae.But not all of the laser’s heat is used.Depending on the condition of the algae and the rate of photosynthesis,some of the heat is shot back into the water,creating sound waves,Dubinsky said.With a special underwater microphone,researchers are able to analyze the strength of the sound waves and determine the health of the algae and the condition of the surrounding water.
“Algae suffering from lead poisoning,like waste discharged from battery and paint manufacturing plants,will produce a different sound than those suffering from lack of iron or exposure to other toxins,” said researcher Yulia Pinchasov.She said that testing algae photosynthesis can determine water quality more accurately and easily than labor­intensive methods now used like chemical and radioactive carbon testing.
【小题1】The underlined word “algae” in Paragraph 2 probably refers to a kind of________.

A.instrument B.plant
C.wood D.pollutant
【小题2】Why is the algae tested?
A.Because it floats on the water.
B.Because it can have photosynthesis.
C.Because it is the first to be polluted.
D.Because it can produce different sounds.
【小题3】We can infer from the passage that________.
A.algae can produce a loud sound when polluted
B.algae can die easily from pollution
C.photosynthesis of the algae can only be caused by sunlight
D.photosynthesis of the algae is related to water quality
【小题4】What would be the best title for the passage?
A.Scientists Listen to Plants to Find Water Pollution
B.A Prototype Tester Is Used to Determine Water Pollution
C.The Importance of Photosynthesis of the Algae
D.The Problem of Chemical and Radioactive Carbon Testing

查看答案和解析>>

同步练习册答案