Lesson 35 Space odyssey太空探索
First listen and then answer the following question.
听录音,然后回答以下问题。
When will it be possible for us to think seriously about colonising Mars?
The Moon is likely ...
Lesson 43 Are there strangers in space?宇宙中有外星人吗?
First listen and then answer the following question.
听录音,然后回答以下问题。
What does the 'uniquely rational way' for us to communicate with other inte...