Scientists think that there has been life on earth for millions of years. However, we haven’t found life on other planets yet. The earth is a planet and it goes around the sun. And there are seven other planets that also go around the sun. The sun and its planets are called the solar system. The solar system is a small part of the universe.
Scientists have launched many spaceships to explore other planets in the solar system. Some spaceships have gone beyond the solar system. However, no one has discovered any life in space yet.
Why has no one from other planets sent us a message? Have they tried to send information to us? With so many stars in space, are we alone, or is there life on other planets in space?
1 ．请写出文中划线处 “it” 指代的内容。 _______
2 ． According to the passage, the solar system includes __________ and __________.
3 ． How many planets are there in the solar system according to the passage?
________________________________________________
4 ． Have any spaceships gone beyond the solar system?
_________________________________________________
1 ． Fill in the blank with the right words according to the passage. ________
答案
1 ． the earth
2 ． the sun its planets
3 ． Eight./8/There are eight planets in the solar system./There are 8 planets in the solar system.
4 ． Yes, they have./Yes.
5 ． the solar system
【分析】
文章是科学家对宇宙的一些研究情况的科普。
1 ．
根据 “The earth is a planet and it goes around the sun.” 可知，地球是一颗行星，它绕着太阳转， it 指的是 “ 地球 ” ，故填 the earth 。
2 ．
根据 “The sun and its planets are called the solar system.” 可知，太阳及其行星被称为太阳系。故填 the sun ， its planets 。
3 ．
根据 “The earth is a planet and it goes around the sun. And there are seven other planets that also go around the sun. The sun and its planets are called the solar system.” 可知，太阳系中有 8 大行星，故填 Eight./8./There are eight planets in the solar system./There are 8 planets in the solar system.
4 ．
根据 “Some spaceships have gone beyond the solar system.” 可知，一些宇宙飞船已经超越了太阳系，故填 Yes, they have./Yes.
5 ．
根据 “The earth is a planet and it goes around the sun. And there are seven other planets that also go around the sun. The sun and its planets are called the solar system. The solar system is a small part of the universe.” 可知，地球围绕着太阳转，太阳及其行星被称为太阳系，而太阳系是宇宙的一小部分，所以图片箭头所指的部分应该是太阳系，故填 the solar system 。
