1、本网站免费注册后即可以下载，点击开通VIP会员可无限免费下载！
2、资料一般为word或PPT文档。建议使用IE9以上浏览器或360、谷歌、火狐浏览器浏览本站。
3、有任何下载问题，请联系微信客服。
扫描下方二维码，添加微信客服
crowded adj. 拥挤的
polluted adj. 被污染的
rapid adj. 快的, 迅速的
increase n. 增加
passenger n. 乘客
uncomfortable adj. 使人不舒服的
oxygen n. 氧气
tasty adj. 味道好的
specially adv. 专门地，特地
float vi. 漂浮；飘浮
compare vt. & vi. 比较
interplanetary adj. 行星间的
network n. 网络
challenging adj. 挑战性的
rapidly adv. 快地，迅速地
(all) over again 再；重新
at a/the speed of 以……的速度
in the form of 以……的形式
compare to/with 与……相比
Pre-reading
Daniel wants to find out more about life in space in the future. He has found the article by a famous scientist who thinks humans could live on Mars by the next century.
Mars
the surface of Mars
The surface of Mars is a
little like the surface of Earth.
It may be difficult to imagine when people will live on the planet Mars.
The lowest temperature will be -133℃ (degrees centigrade) and the highest will be 27 ℃.
spacecraft
are too slow to carry large numbers of people to Mars
travel at half the speed of light