二、重要句型
　　1. Our own planet, the Earth, is becoming more and more crowded and polluted because of the rapid increase in population.
　　　我们自己的行星，地球，因为人口的快速增长，正变得越来越拥挤，污染越来越严重。
　　2. It is hoped that people could start all over again and build a better world on Mars.
　　　人们有望能够在火星上重新开始，建设一个更美好的世界。
　　3. With the development of technology, by the year 2100, the journey might only take about 20 minutes in spacecraft that travel at the speed of light!
　　　随着技术的发展，到2100年，乘坐以光速飞行的宇宙飞船（到火星）只要花20分钟左右！
　　4. So far, nobody knows whether there would be enough water or oxygen on Mars for people there. 到目前为止，没人知道火星上是否有足够的水或氧气供人们（生存下来）。
　　5. The gravity on Mars is only about three - eighths of that on the Earth.
　　　火星上的重力大约只有地球上的八分之三。
　　6. Life on Mars would be interesting as well as challenging.
　　　火星生活不仅有挑战性，还会很有趣。
　　7. It takes Mars about two Earth years to circle around the Sun once.
　　　火星围绕太阳转一圈大约需要两个地球年。
　　8. I’m not sure if it’s worth the risk. 我不确定是否值得冒这个险。
　　9. Here is a guide to living on Mars in the future. 这里是未来在火星居住的一份指南。
　　10. They make us feel like we are really inside the games!
　　　它们让我们感觉真的置身于游戏中！