阅读下面短文并回答问题，然后将答案写到答题卡相应的位置上（请注意问题后的词数要求）。
【1】Sometime early in the next century, human beings will move into habitats on Mars. They will live there for about a year, and then will be replaced with another set of pioneers. The establishment of this base on Mars will advance our knowledge of the solar system and aid in our understanding of the earth.
【2】We already know that Mars is like the earth in many ways: general size; presence of water; length of day; range of temperatures. These similarities have caused many people to consider a century-long project: to terraform Mars. Terraforming means changing a planet’s surface so that Earth’s life forms can survive there. This concept, previously found only in science fiction is now being seriously considered by scientists.
【3】Terraforming Mars is theoretically simple: add nitrogen and oxygen to the atmosphere; pump water to the surface; and add the earth’s plants and animals in the order in which they developed on Earth. But it will take at least 300 years.
【4】Some people think that such a project is too huge for humans to accomplish, but there are very good reasons to make the attempt. The earth now contains some 7 billion people, and no one knows how many humans the earth can support. Our very existence and numbers are threatening many other species with extinction. We also have had some experience with terraforming our own planet: changing the landscape, the atmosphere and the climate. At present, we are aware of the importance of terraforming the earth as we try to control global warming, air and water pollution, and protect some natural habitats.
【5】While the future of such a project is daunting(令人生畏的), it is not impossible. Even if earth-bound societies come and go in the next 300 years, the project can continue through the work of the Mars settlers without the need for constant backing from earth.
【6】The future existence of humanity may very well depend on our ability to terraform Mars.
小题1:What’s the purpose of establishing a base on Mars in the 1st paragraph? ( not more than 12 words)
小题2:List three ways Mars is like the earth. ( not more than 9 words)
小题3:What’s the author’s attitude towards the project? (1 word)
小题4:What does the future existence of humanity most probably rely on? ( not more than 6 words)
小题5:What’s the main idea of this passage? (not more than 8 words)
