This morning, a Virgin Atantin 747 Jumbo Jet became the first commercial airplane to fly on biofuel. The short flight from London to Amsterdam used a blend of 20% babassu(棕榈) oil mixed with 80% conventional jet fuel.

What was really exciting about the flight was the fact that the engine did not have to be altered in any way for the biofuel to work While this is a great initial step in trying to reduce CO₂(carbon-dioxide)emissions(排放)from airplanes. there are a lot of hurdles (障碍)that still need to be overcome.

First and foremost, unlike the normal fuel used to run airplanes (known as Jet A),biofuel freezes at high altitudes. Also, Jet‘A’fuel burns consistently (at the same pace),which means it provides a safe and reliable fuel for long flights--engineers are not sure if biofuel will be able to do the same.

The biggest hurdle to a full biofuel switch is our ability to be able to grow enough crops that can be converted to biofuel. There are two concerns that scientists have in this matter – the first is that the land to grow the extra crops will come from clearing more of our forests and the second is that since it competes with what we eat, the price of food will go up.

However, Richard Branson of Virgin Airlines, envisions that if biofuel starts to replace oil on a greater basis, it will be manufactured from algae（藻类）produced in sewage treatment plants, not from food sources.

Birgin Airlines is not the only one trying to look for alternative fuel sources. Earlier this year, an Airbus A380 used another alternative fuel－a man-made mix of gas-to-liquid, in one of its four engines. The flight was tested by Rolls Royce (manufacturer of jet engines), in partnership with Shell (an oil company). Rolls Royce is also working with Air New Zealand on a similar project.

While a complete switch to alternative fuel may take years, it is very encouraging to see airlines, oil companies and airplane manufacturers all coming together to try to make it happen!

1.．Why does Virgin Airlines try to replace normal fuel with biofuel?

A．To cut down the flight cost of the company.

B．To remove some hurdles for the biofuel to work.

C．To reduce CO2 emissions from airplanes.

D．To test plane engines on biofuel.

2.．Which is NOT true for a full biofuel switch of airplanes?

A Biofuel cannot run for long flights.                  

B．Biofuel cannot work at high altitudes.

C．Man has not enough land to grow extra crops for biofuel. 

D．It’s not easy for sewage treatment plants to manufacture biofuel.

3.．One of the hurdles to be overcome for a full biofuel switch is to          .

A．alter the engine for airplanes

B．make biofuel burn consistently

C．open more land to grow more crops

D．develop sewage treatment plants

4.．We can infer from the last paragraph that          .

A．there is a long way to go for a complete switch to alternative fuel

B．it won’t be long before alternative fuel comes into use

C．airlines, oil companies and airplane manufacturers are reliable

D．alternative fuel has a bright future

5.．Which of the following can best serves as the title of this passage?

A．Biofuel-Alternative Fuel Sources.

B．The First Commercial Flight Powered by Biofuel.

C．How to Reduce CO2 Emissions from Airplanes.

D．Vigin Airlines Trying to Alter Fuel Sources.

 

From a plane we can see the fields, cities, mountains or seas below. If we go into space, we see more and more of the earth. People and man-made satellites have been sent out into space to look at the earth carefully and people have learnt more about the earth in the last few years.

The sea looks very beautiful when the sun is shining on it. But it can be very terrible when there is a strong wind.

The sea is very big. It nearly covers three quarters of the earth. The sea is also very deep in some places. There is one place and at that place the sea is about 11 kilometers deep. The highest mountain in the world is about 9 kilometers high. If that mountain was put into the sea at that place, there would be still 2 kilometers of water above it!

In most parts of the sea, there are many kinds of fishes and plants. Some live near the top of the sea. Others live deep down. There are also a lot of small living things, and lots of fishes live by eating them.

The sea can be very cold. When people go down, the sea becomes colder and colder. Only some men can go down into the deep sea. But, in 1970, five women scientists (科学家) lived in the deep sea for fourteen days.

1.This passage is_________.

A．a short story                           B．for science reading

C．a piece of news                         D．a report

2.The sea covers about _______of the earth.

A One third         B. One fourth

C. Two quarters    D. Three fourths

3. Which of the following is NOT true?

A．The sea is usually beautiful when the sun is shining.

B．The sea is always very terrible when the wind blows hard.

C．The highest mountain is in the deepest place of the sea.

D．The deeper the people go into the sea, the colder they will feel.

4. The last sentence “But, in 1970, five women scientists lived in the deep sea for fourteen days.” means that________.

A．women wanted to live in the deep sea for a long time

B．women could go deeper into the sea than men

C．women liked living in the deep sea better than men

D．women could do the same work as men

 

Empty Deserts
In the 19^th century Americans from the eastern states moved out west to settle in the rich new lands along the Pacific coast. The most difficult part of their trip was crossing the “Great American Desert in the western part of the United States by horse and wagon.
The western desert can be very dangerous. There is little water and there are few trees. But the desert also has scenery of great beauty. Tall towers of red and yellow stone rise sharply from the flat sandy valley floor. The scene has been photographed many times and appears in movies and in TV.
In Arizona, man made dams across the Colorado River have made two large lakes in the middle of the dry desert country. At Lake Powell, the red stone arch of Rainbow Bridge rises high above the blue lake.
There are few roads. Many areas of Lake Powell’s shore can only be reached by boat or on foot. But hikers in this empty desert land sometimes find very old native American pictures, painted on the rocks.
In Death Valley, California, the summer temperature rises to 130 degrees. There is less than two inches of rain each year. Death Valley is the lowest place in America---- 925 meters below sea level. In the 1800s, many travelers died when they tried to cross this waterless valley in the terrible heat.
Although the desert is dry and seems empty, there is plenty of life if you look closely. Small insects, snakes and rats have learned how to live in the desert heat. They live under ground and come out at night, when it is cool. Plants such as cacti need very little water.  When it does rain in the desert (sometimes only once or twice a year), plants grow quickly, and flowers open in a single day. For a short time, the desert is covered with brilliant colors.
【小题1】In the 19^th century, Americans moved from the east to the west because they ______.

A．enjoy the trip	B．wanted to make their home there
C．wanted to find new grassland there	D．had no water to drink

【小题2】From the passage, we can conclude that ______.

A．the western desert is a good place for people to live in

B．there is little water but there are many trees in the desert

C．the desert is dangerous but it is full of life

D．till now, people know little about the desert

【小题3】 If you want to find some old native American pictures painted on the rock you must go ______.

A．on foot

B．by boat

C．by car

D．by plane

【小题4】In the 1800s many travelers died in Death Valley because of ______.

A．illness	B．high temperature
C．cold weather	D．poisonous water

【小题5】In the desert, animals will die ______.

A．if they move about	B．if they cannot make holes underground
C．if they come out at night	D．if they drink much water

Water costs money．In some places water is hard  31 ．What 32 when a town has these problems？A small town in California found a happy 33 ．

Very 34 rain ever fell there．The town had no water35 ．The water it used was 36  from a river 300 miles away．As more people  37  live in the town  38  water was needed．Now water  39  to be brought in from 600 miles away．All these cost  40 money．

The town 41 a plan．It found 42   to clean its “dirty” water．Once the cleaned water was reused  43  many ways．Five  44  lakes were built．Here people could swim and fish and go  45 ．They  46  have picnics in their new parks．Farmers had more water 47  their crops．New factories can be built，now that they have the promise of  48 ．

In most places，water is used and thrown 49．The town that saved 50 water has saved the town！

1.    

A．supplying

B．getting

C．to get

D．to supply

2.    A．happens     B．happening    C is happened     D．happened

3.    A．key         B．answer       C answering    D．way

4.    

A．little

B．a little

C．few

D．a few

5.    A．of itself   B．of its own  C．for its own    D for itself

6.    

A．fetch

B．take

C．brought in

D．guided

7.    

A．come to

B．came to

C．coming to

D．came for

8.    

A．many

B．plenty of

C．more

D．many more

9.    

A．has

B．had

C．must

D．needed

10.  

A．many

B．a few

C．a great many

D．a lot of

11.  

A．put

B．made

C．supply

D．noticed

12.  

A．a way

B．ways

C．an answer

D．a key

13.  

A．for

B．by

C．at

D．in

14.  

A．man-making

B．man-make

C．man-made

D．man made

15.  

A．boating

B．to boat

C．to boating

D．on boating

16.  

A．must

B．could

C．needed

D．had to

17.  

A．as

B．with

C．for

D．to

18.  

A．water enough

B．enough water

C．crops enough

D．enough crops

19.  

A．off

B．of

C．away

D．out of

20.  

A．it’s

B．its

C．one’s

D．his

 

Some scientists say that animals in the oceans are increasingly threatened by noise pollution caused by human beings.

The noise that affects sea creatures comes from a number of human activities. It is caused mainly by industrial underwater explosions, ocean drilling, and ship engines. Such noises are added to natural sounds. These sounds include the breaking of ice fields, underwater earthquakes, and sounds made by animals themselves.

Decibels (分贝) measured in water are different from those measured on land. A noise of one hundred and twenty decibels on land causes pain to human ears. In water, a decibel level of one hundred and ninety－five would have the same effect.

Some scientists have suggested setting a noise limit of one hundred and twenty decibels in the oceans. They have observed that noises at that level can frighten and confuse whales（鲸鱼）.

A team of American and Canadian scientists discovered that louder noises can seriously injure some animals.

The research team found that powerful underwater explosions were causing whales in the area to lose their hearing. This seriously affected the whales' ability to exchange information and find their way. Some of the whales even died. The explosions had caused their ears to bleed and become infected(被感染的).

Many researchers whose work depends on ocean sounds are against a limit of one hundred and twenty decibels. They say such a limit would mean an end to important industrial and scientific research.

Scientists do not know how much and what kinds of noises are harmful to ocean animals. However, many scientists don’t think that noise is a greater danger than they believed. They want to prevent noises from harming creatures in the ocean.

36．According to the passage, which of the following is increasingly dangerous to sea creatures?

A. The sound of cars.

B. The sound of voices.

C. Man-made noise pollution.

D. The sound of steps.

37．According to the passage, natural sounds include all of the following EXCEPT________.

A. sounds made by animals themselves               B. ocean drilling

C. underwater earthquakes                                D. the breaking of ice fields

38．Which of the following is discussed in the third paragraph?

A. The same noise level produces a different effect on land and in the ocean.

B. Different places may have different types of noises.

C. The decibel is not a right unit (单位) for measuring underwater noise.

D. Different ocean animals may have different reactions to noises.

39． Which of the following is true of whales?  

A. They won't be confused by noises.

B. They are deaf to noises.

C. Their ability to reproduce will be lowered by high-level noises.

D. Their hearing will be damaged by high-level noises.

40．According to the passage, what will scientists most probably do in the future?

A. They will work hard to reduce ocean noise pollution.

B. They will protect animals from harmful noises.

C. They will try to set a limit of 120 decibels.

D. They will study the effect of ocean noise pollution.