I．词汇
A.）根据句意及首字母提示补全下列单词，使句子完整填入恰当的单词。
1. Food will be in the form of ___________ (small round pieces of medicine) on Mars.
2. Should we be able to ____________ (grow and improve) plants that can grow on Mars?
3. Our Earth is becoming more and more __________ (拥挤的) and ___________ (被污染的).
4. The meeting began with a _________________(讨论) about a survey .
