Ⅰ. 完形填空
阅读下面的短文,从每题所给选项中选出可以填入空白处的最佳选项。
Every day the Sun gives off a great deal of heat and makes us feel hot. 1 we receive only a small part of 2 because the Sun is so far away from us and its heat loses most of its 3 when it reaches the Earth. Life on the Earth 4 the Sun. Day after day we see its light and feel its 5. The Sun is far away from the Earth. It is 6 million miles away from the Earth. Scientists think that there has been life on the Earth for millions of years. However, we haven't found life on other planets 7. The Earth is a planet and it 8 around the Sun. And there are seven other planets 9 also go around the Sun. Mars is the 10 planet from the Sun in our solar system(太阳系). Its diameter(直径) is 53% as wide as 11 of the Earth. Mars goes around the Sun 12 a distance of about 228 million kilometres. You can tell which planet is Mars 13 it is bright red in the sky. It looks like a red and orange ball. It's very beautiful. But during spring and summer, strong storms can cover the whole surface of Mars. Scientists have launched many spaceships to 14 other planets in the solar system. Some spaceships have gone beyond the solar system. However, 15 has discovered life in space yet.
( ) 1.
( ) 2.
( ) 3.
( ) 4.
( ) 5.
( ) 6.
( ) 7.
( ) 8.
( ) 9.
( )10.
( )11.
( )12.
( )13.
( )14.
( )15.