Scientists think that there has been life for_
_31_ of years. However we haven’t found life on other planets _
32_ . The earth is a planet and it
_33__ around the sun. Seven other planets also go _
34_ the sun. The sun and its planets are
__35 the solar system. The solar system is a small part of our galaxy.
Scientists __
36_ lots of spacecraft to look at other planets in the solar system, and some spacecraft have gone _
_37_ the solar system. However, no one _
_38_ any life in space yet.
But why has no one from other planets sent us a message ? Have they tried to send _
39_ to us ? _
40_so many stars in the universe, are we alone, or is there life out there in space ? We don’t know.
| 小题1: | | A．thousands | B．millions | C．hundreds | D．billion |
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| 小题2: | | A．already | B．never | C．yet | D．just |
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| 小题5: | | A．called | B．call | C．calling | D．calls |
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| 小题6: | | A．send | B．sent | C．have sent | D．will send |
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| 小题8: | | A．discovered | B．discovers | C．has discovered | D．have discovered |
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| 小题9: | | A．message | B．informations | C．information | D．news |
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| 小题10: | | A．With | B．Have | C．Use | D．Because |
|
