Is there life on Mars? We do not know. We are sure that earth people do not like to live on Mars. Earth people need oxygen to breathe. There is almost no oxygen on Mars.

　　Living on Mars would be like living on a very high mountain. There would be little air. It might be 50 degree above zero at noon and 100 degree below zero at night.

　　Many people think there may be plants on Mars. We know that Mars has carbon. This is a kind of material found in all plants and animals on earth. Through a telescope, Mars looks red. In some places, it seems gray. At times, the gray colour turns gray-green, then brown, then gray again. The gray-green colour may be a kind of plant life changing colour with seasons.

　　Will man go to Mars one day? If they do, they will have to take along their own oxygen, food, clothing, and shelter（住所）.

(1) What do you think is the main reason why men can't live on Mars? Because

[　　]

A．living on Mars is like living on a high mountain

B．there is no oxygen on Mars

C．there are not any plants or animals on Mars

D．on Mars it is too hot at noon and too cold at night

(2) The story does not say this, but from what we have read, we can tell that

[　　]

A．someday we may know if there is life on Mars

B．men must take food and clothing with them when they go to Mars

C．people on Mars need no air to breathe

D．the plants on Mars are red

(3)“Carbon”is _______.

[　　]

A．a kind of food

B．a gas only found on the earth

C．a kind of material whose colour is gray

D．a kind of material that almost all living things need

(4) The main idea of the whole story is that________.

[　　]

A．there may be life on Mars

B．earth people could live on Mars

C．Mars turns its colour with seasons

D．Man will one day land on Mars

(5) Which of the following does this story lead you to believe？

[　　]

A．Some earth people have already visited Mars.

B．There is a lot of oxygen and carbon on Mars.

C．There may be strange forms of life on Mars.

D．Mars is earth people's future home.

　Is there life on Mars? We do not know. We are sure that earth people do not like to live on Mars. Earth people need oxygen to breathe. There is almost no oxygen on Mars.

　　Living on Mars would be like living on a very high mountain. There would be little air. It might be 50 degree above zero at noon and 100 degree below zero at night.

　　Many people think there may be plants on Mars. We know that Mars has carbon. This is a kind of material found in all plants and animals on earth. Through a telescope, Mars looks red. In some places, it seems gray. At times, the gray colour turns gray-green, then brown, then gray again. The gray-green colour may be a kind of plant life changing colour with seasons.

　　Will man go to Mars one day? If they do, they will have to take along their own oxygen, food, clothing, and shelter（住所）.

(1) What do you think is the main reason why men can't live on Mars? Because

[　　]

A．living on Mars is like living on a high mountain

B．there is no oxygen on Mars

C．there are not any plants or animals on Mars

D．on Mars it is too hot at noon and too cold at night

(2) The story does not say this, but from what we have read, we can tell that

[　　]

A．someday we may know if there is life on Mars

B．men must take food and clothing with them when they go to Mars

C．people on Mars need no air to breathe

D．the plants on Mars are red

(3)“Carbon”is _______.

[　　]

A．a kind of food

B．a gas only found on the earth

C．a kind of material whose colour is gray

D．a kind of material that almost all living things need

(4) The main idea of the whole story is that________.

[　　]

A．there may be life on Mars

B．earth people could live on Mars

C．Mars turns its colour with seasons

D．Man will one day land on Mars

(5) Which of the following does this story lead you to believe？

[　　]

A．Some earth people have already visited Mars.

B．There is a lot of oxygen and carbon on Mars.

C．There may be strange forms of life on Mars.

D．Mars is earth people's future home.

　　Is there life on Mars（火星）? We do not know. But we are sure that earth people do not live on Mars. Earth people need oxygen to breathe. There is almost no oxygen on Mars. It is uncertain exactly how life arose on Earth, so it is difficult to determine how common such mechanisms are. But if life also arose on Mars, this would show that those mechanisms operated not just once, but twice, arguing that life may well be common elsewhere.

　　Living on Mars would be like living on a very high mountain. There would be little air. It might be 50 degree above zero at noon and 100 degree below zero at night.

　　Many people think there may be plants on Mars. We know that Mars has carbon. This is a kind of material found in all plants and animals on earth. Through a telescope, Mars looks red. In some places, it seems gray. At times, the gray colour turns gray--green, then brown, then gray again. The gray-green colour may be a kind of plant life changing colour with seasons.

　　Mars is a spectacular（引人入胜）place, and will remain so even if it is finally proved to be lifeless. Today, we don't know for sure if there is or ever was life on Mars. But one thing is certain--one day, there will be.

　　Will man go to Mars one day? If they do, they will have to take along their own oxygen, food, clothing, and shelter（住所）.

(1)What do you think is the main reason why men can't live on Mars? Because ________ .

[　　]

A．living on Mars is like living on a high mountain

B．here is no oxygen on Mars

C．there are not any plants or animals on Mars

D．on Mars it is too hot at noon and too cold at night

(2)The story does not say this, but from what we have read, we can tell that ________ .

[　　]

A．someday we may know if there is life on Mars

B．men must take food and clothing with them when they go to Mars

C．people on Mars need no air to breathe

D．the plants on Mars are red

(3)The main idea of the whole story is that ________ .

[　　]

A．there may be life on Mars

B．earth people could live on Mars

C．Mars turns its colour with seasons

D．man will one day land on Mars

(4)Which of the following does this story lead you to believe? ________ .

[　　]

A．Some earth people have already visited Mars

B．There is a lot of oxygen and carbon on Mars

C．There may be strange forms of life on Mars

　　Is there life on Mars（火星）? We do not know. But we are sure that earth people do not live on Mars. Earth people need oxygen to breathe. There is almost no oxygen on Mars. It is uncertain exactly how life arose on Earth, so it is difficult to determine how common such mechanisms are. But if life also arose on Mars, this would show that those mechanisms operated not just once, but twice, arguing that life may well be common elsewhere.

　　Living on Mars would be like living on a very high mountain. There would be little air. It might be 50 degree above zero at noon and 100 degree below zero at night.

　　Many people think there may be plants on Mars. We know that Mars has carbon. This is a kind of material found in all plants and animals on earth. Through a telescope, Mars looks red. In some places, it seems gray. At times, the gray colour turns gray--green, then brown, then gray again. The gray-green colour may be a kind of plant life changing colour with seasons.

　　Mars is a spectacular（引人入胜）place, and will remain so even if it is finally proved to be lifeless. Today, we don't know for sure if there is or ever was life on Mars. But one thing is certain--one day, there will be.

　　Will man go to Mars one day? If they do, they will have to take along their own oxygen, food, clothing, and shelter（住所）.

(1)What do you think is the main reason why men can't live on Mars? Because ________ .

[　　]

A．living on Mars is like living on a high mountain

B．here is no oxygen on Mars

C．there are not any plants or animals on Mars

D．on Mars it is too hot at noon and too cold at night

(2)The story does not say this, but from what we have read, we can tell that ________ .

[　　]

A．someday we may know if there is life on Mars

B．men must take food and clothing with them when they go to Mars

C．people on Mars need no air to breathe

D．the plants on Mars are red

(3)The main idea of the whole story is that ________ .

[　　]

A．there may be life on Mars

B．earth people could live on Mars

C．Mars turns its colour with seasons

D．man will one day land on Mars

(4)Which of the following does this story lead you to believe? ________ .

[　　]

A．Some earth people have already visited Mars

B．There is a lot of oxygen and carbon on Mars

C．There may be strange forms of life on Mars