It has been a long time for human to make _____ to reach the moon.

The earth is the only planet that scientists are certain has life .What does the earth have that the other planets don’t ? For one thing , the earth has just the right temperature . As the third planet from the sun , the earth seems to be just the right distance away . The planets that are closer to the sun are so hot that their surfaces bake in the sun . The farthest planets are cold balls .

When the earth developed— which scientists believe may have happened about billions of years ago , many gases covered the earth . The gases caused the earth to be hot . But something wonderful happened . The temperature was just right for thick clouds to form . It rained very hard for a very long time . This gave the earth its oceans . Water made it possible for plants to grow . The plants created oxygen in the atmosphere . Oxygen is the gas that humans and animals breathe .

Only one other planet in the solar system seems to be something like the earth . That planet is Mars . Mars is smaller than the earth , and it is quite a bit cooler . But it is not too cold for humans . On some days , the temperatures are as cold as a winter day in the northern United States . If you wore a special spacesuit , you could walk around on Mars . You would have to bring your own air to breathe , though . The air on Mars is too thin to breathe . Mars has the largest volcano in the solar system . It is sixteen miles high . The highest volcano on the earth is five miles high . The most unexpected sight on Mars is dried-up river beds . Scientists believe that Mars was once much wetter that it is now . Does this mean there could have been living things on Mars ? Scientists are not sure , but there has been no sign so far .

1.It is the       on the earth that makes life possible .

A．temperature       B．water             C．oxygen           D．temperature , water and oxygen

2.The underlined phrase “ the third planet ” means       .

A．the sun           B．the earth          C．the moon         D．Mars

3.Which planet in the solar system is most like the earth ?

A．Mars .            B．Moon .            C．Sun .             D．Mars and Moon .

4.Which of the following is TRUE ?

A．The earth has a history of about 4 million years .

B．There is no air on Mars .

C．The largest volcano on Mars is over three times higher than the highest one on the earth

D．Scientists believe there are living things on Mars .

5.The best title for the passage should be        .

A．Living Things on Our Earth                 B．The Moon

C．Living Things on the Moon                 D．Mars Is Most Like the Earth

_____from the moon ,our earth with water ____70% of its surface, appears as a “blue ball”

 _____ is known to everybody, the moon travels round the earth once every month.

A. It    B. As        C. That       D. What

根据上下文及所给的首字母或汉语意思填写单词(每条横线上只能填写一个单词) 

注意：给出首字母的词，需将首字母一起填写到答题卷上

1.The m           of us voted for Mr. Red, who then became chairman of the committee.

2.Remember, tasks are only a m            to an end; goals are that end.

3.All efforts of cloning an animal will be in v            if there is not enough diversity in the group to overcome illnesses.

4.Don’t b             him with that now; he is busy preparing for an exam.

5.Is it c              for you to meet me at the airport next Monday afternoon?

6.In a courtroom it is sometimes difficult to recognize who is i             and who is guilty.

7.If I’m not m            , Colorful Clouds Chase the Moon is a Chinese song, not a Japanese one.

8.Generally speaking, he thought that lower class people betrayed themselves with their r             whenever they spoke.

9.The war i              the trade between the two countries.

10.The book tells the story of Max, who behaves badly and is sent to his room without dinner as a ______________(惩罚).