At the moment, it may be difficult to imagine, but many people believe that, by the year 2100, we will live on the planet Mars. Our own planet, Earth, is becoming more and more crowed and polluted. Luckily, we can start again and build a better world on Mars. Here is what life could be like.

First of all, transport should be much better. At present, our spaceships are too slow to carry large numbers of people to Mars — it takes months. However, by 2100, spaceship can travel at half the speed of light. It might take us two or three days to get to Mars!

Secondly, humans need food, water and air to live. Scientists should be able to develop plants that can be grown on Mars. These plants will produce the food and air that we need. However, can these plants produce water for us ? There is no answer now.

There is a problem for us to live on Mars. Mars pulls us much less than the Earth does. This will be dangerous because we could easily jump too high and fly slowly away into space. To prevent this, humans on Mars have to wear special shoes to make themselves heavier.

Life on Mars will be better than that on Earth in many ways, People will have more space. Living in a large building with only 10 bedrooms is highly possible. Many people believe that robot will do most of our work, so we have more time for our hobbies.

There will probably be no school on Mars. Every student will have a computer at home which is connected to the internet. They can study, do their homework and take exams in online schools. Each student will also have their own online teacher called “e-teacher”.

However, in some ways, life on Mars may not be better than that on the earth today. Food will not be the same — meals will probably be in the form of pills and will not be as delicious as they are today, Also, space travel will make many people feel ill. The spaceship will travel fast but the journey to Mars will probably be very uncomfortable.

46. According to the text, by the year 2100, some of us will possibly live __________ .

 A. on the moon                        B. on Mars          

 C. under the sea                       D. in the sun

47. So far, how long will it take us from the earth to Mars by spaceship ?

 A. Two or three days                   B. A few years

 C. A few days                         D. A few months

48. In the future, the students on Mars ____________ .

A. needn’t study at all     

B. will study mainly in a classroom

C. will meet each other face to face every day   

D. will study mainly through the internet

49. Life on Mars will be better than life on the earth because ___________ .

A. there will be more space and less work to do    

B. only a few people will live there

C. there will be much delicious food     

D. all students don’t need to do any homework

50. According to the text, which of the following about Mars is NOT true ?

 A. Transport will be much better and faster.  

 B. We need to develop a special plant which can produce water.

 C. Food will be much more tasty.

 D. On Mars, we can jump higher than on the earth.

Remember what weight is? Weight is the gravitational pull on an object. If, somehow, the pull of gravitation changes, then the weight of the object changes. The mass of the object, the amount(数量)of matter it is made of, does not change.

If a bag of sugar weighs 6 kilograms on earth, what will it weigh on the moon? It will weigh one kilogram on the moon, 1/6 of its weight on the earth.

Here on the earth we usually talks as if weight and mass were the same thing. We use weight as a way of measuring mass. On the earth this is very convenient. A mass of sugar that weighs 6 kilograms in California will weigh about 6 kilograms in Hawaii or Canada or Germany. Because the force of gravitation in each place is practically the same.

As long as we stay on earth, using weight to measure mass works pretty well. Now, however, men have left the earth. Suddenly we realize that weight and mass are not the same thing! Away from the earth the force of gravitation changes. As the pull gravitation changes, weight changes, but the mass of an object stays the same anywhere in the universe—whether it is on earth, on the moon, or on Mars.

Have you ever wondered why the pull of gravitation on the moon is only 1/6 of the pull on the earth? Here is a reason. When the mass is less, gravitation is less. The moon has less mass than the earth. Since the moon has much less mass than the earth, it has much less gravitational force than the earth.

1.Which of the following is NOT true?

A. Few people on the earth would pay much attention to the difference between weight and mass.

B.The weight of an object hardly changes wherever on the earth it is weighed.

C.The weight of an object becomes less on the moon because the moon is far away from the earth.

D.Mass is a concept(概念)more important than weight in the study of the universe.

2.The amount of mass depends on 　　  .

A. the weight of an object?　　　　　　　　　　　　　　 B.the place where it is measured

C.the size of an object?　　　　　　　　　　　　　　　　  D.the amount of matter it is made of

3.An astronaut, who weighed 30 pounds on the moon, is back on earth and now weighs 165 pounds. How much weight did he lose during his flight back to the earth?

A.115 pounds.　　　　　　   B.2.5 pounds.?　　　　    C.30 pounds.　　　　　　    D.15 pounds.

4.We can infer from the passage that the word “Mars” means 　　  .

A. a faraway place on the earth

B.a place deep down in the ocean

C.a kind of flying equipment like a spaceship

D.a planet which is farther away from the earth than the moon is

 

Remember what weight is? Weight is the gravitational pull on an object. If, somehow, the pull of gravitation changes, then the weight of the object changes. The mass of the object, the amount(数量)of matter it is made of, does not change.

If a bag of sugar weighs 6 kilograms on earth, what will it weigh on the moon? It will weigh one kilogram on the moon, 1/6 of its weight on the earth.

Here on the earth we usually talks as if weight and mass were the same thing. We use weight as a way of measuring mass. On the earth this is very convenient. A mass of sugar that weighs 6 kilograms in California will weigh about 6 kilograms in Hawaii or Canada or Germany. Because the force of gravitation in each place is practically the same.

As long as we stay on earth, using weight to measure mass works pretty well. Now, however, men have left the earth. Suddenly we realize that weight and mass are not the same thing! Away from the earth the force of gravitation changes. As the pull gravitation changes, weight changes, but the mass of an object stays the same anywhere in the universe—whether it is on earth, on the moon, or on Mars.

Have you ever wondered why the pull of gravitation on the moon is only 1/6 of the pull on the earth? Here is a reason. When the mass is less, gravitation is less. The moon has less mass than the earth. Since the moon has much less mass than the earth, it has much less gravitational force than the earth.

1.Which of the following is NOT true?

A. Few people on the earth would pay much attention to the difference between weight and mass.

B.The weight of an object hardly changes wherever on the earth it is weighed.

C.The weight of an object becomes less on the moon because the moon is far away from the earth.

D.Mass is a concept(概念)more important than weight in the study of the universe.

2.The amount of mass depends on 　　  .

A. the weight of an object?　　　　　　　　　　　　　　 B.the place where it is measured

C.the size of an object?　　　　　　　　　　　　　　　　  D.the amount of matter it is made of

3.An astronaut, who weighed 30 pounds on the moon, is back on earth and now weighs 165 pounds. How much weight did he lose during his flight back to the earth?

A.115 pounds.　　　　　　   B.2.5 pounds.?　　　　    C.30 pounds.　　　　　　    D.15 pounds.

4.We can infer from the passage that the word “Mars” means 　　  .

A. a faraway place on the earth

B.a place deep down in the ocean

C.a kind of flying equipment like a spaceship

D.a planet which is farther away from the earth than the moon is

 

Working outside the International Space Station （ISS）, an astronaut is suddenly hit by a piece of space debris（碎片）that damages his spacesuit．Alarmed, he realizes he’s just seconds from disaster．Moving fast, his prepared robot partner slaps（拍打）an auto-patch over the tear in his spacesuit．Huge sighs of relief fill the ISS．Inside, the astronaut responsible for saving the spacewalker’s life controls everything the robot avatar has done — including rescuing its human partner — while it works outside the space station．

R2:The Real Deal

A robot companion can come in handy to space travelers, whether they’re as far away as Mars or as close as a space station or moon base．Space-travelling avatars, controlled remotely by humans are still a concept．But earlier in the year 2011, NASA sent a humanoid robot into space for the first time．It’s called R2, short for Robonaut 2．The robot was delivered by the space shuttle Discovery and will remain on the ISS to be tested．

NASA expects robots like R2 to be a huge help to astronauts．“Our goal is for robots to work side by side with humans,” says NASA’s Matt Ondler．R2 is controlled by humans using laptops． It’s programmed to perform a number of small tasks, such as “find an object．” In most situations, humans are still far better with their hands than robots．But that’s not necessarily true in space, where astronauts must wear bulky spacesuits and heavy gloves．And since they don’t need to eat, breathe, or go to the bathroom, robonauts have the advantage for lengthy jobs．

R2 isn’t ready for spacewalks yet, but NASA hopes that future improvements will make this possible．“Robonauts will help our astronauts with the three D’s: jobs that are dirty, dull, and dangerous,” says Ondler．

To The Moon

Someday the space agency hopes to send R2 to the moon．Sending a robot to the moon will befar less expensive than sending a human．A robot is stronger, can survive in tighter spaces, and doesn’t need air．Even better, robots don’t care how long it takes for NASA to return them to Earth．

Once on the moon, the robonaut could perform experiments, send live video back to Earth, talk to classrooms full of kids, and explore the lunar surface．R2 will be able to move using legs, or by attaching its torso（躯干）to a four-wheeled rover（探测器） and becoming part of vehicle．And when R2’s battery is low, it can plug into a solar-powered recharging station and get some much-needed juice．All in all, a pretty sweet life for a humble robot!

The future R2 would be designed to operate by itself．But for difficult tasks, a human operator would control it like an avatar in a video game．NASA will need people skilled at operating robonauts to ensure the success of future missions．So the next time your mom complains that you’re spending too much time on video games, just tell her you’re training for a job with NASA．

51．In paragraph1, the writer gives a detailed description of a space accident to           ．

       A．stress the danger of an astronaut’s walk in space

       B．tell readers the unforgettable experience of an astronaut

       C．show his concern for the present situation of space walk

       D．introduce what robots are likely to do for astronauts

52．Why does the writer say Robonaut 2 is “The Real Deal”?

       A．It may have the advantage for complex and small tasks at low costs．

       B．It has been programmed to help astronauts with three D’s．

       C．It is flexible and can be easily controlled by humans beings．

       D．It proves to be a good companion for space travelers．

53．By saying“All in all, a pretty sweet life for a humble robot!”, the writer means that           ．

       A．an ordinary robot will be able to move freely in comfortable surroundings

       B．an ordinary robot will enjoy a comfortable life in space like humans on Earth

       C．a future robot will explore the moon easily by using a four-wheeled rover

       D．a future robot is stronger and will handle any difficulty in space easily

54．It can be learned from the passage that            ．

       A．the future R2 will perform experiments without human control

       B．humans are much smarter with their hands than robots in space

       C．someday humans might control an avatar on the moon

       D．sending a human to the moon will cost far less than sending a robot