Book 3 Unit 4 Astronomy：the science of the stars
Ⅰ.联想记忆(根据提示写出相应的词汇以及相关短语)
1．system n．系统
2．in_time及时；迟早，终于→on time 按时→sooner or later迟早
3．harmful adj.有害的→be harmful_to 对……有害
4．in one’s turn轮到某人→It’s one’s turn to do sth.轮到某人做某事→in_turn 轮流；转而→by_turns 轮流
5．prevent...from...阻止；制止→stop...from.../keep...from...阻止做某事
6．now_that既然→since 既然
Ⅱ.构词记忆(根据提示写出相应的词汇及其派生词)
1．theory n．理论，学说→theoretical adj.理论的
2．globe n．地球仪→global adj.全球的
3．like prep.相似；像→unlike prep.不同；不像
4．exist vi.存在→existence n．存在
5．puzzle vt. & vi.(使)迷惑→puzzling adj.令人迷惑的→puzzled adj.感到迷惑的
6．biology n．生物学→biological adj.生物的→biologist n．生物学家
Ⅲ.语境填词(根据提示用适当的单词或短语填空)
1．Now_that(既然) it seems impossible to prevent the war from(阻止) breaking_out(爆发), we will do everything we can to defend our country.
2．If there were no pull(牵引力) of the earth, we would all float_weightlessly(失重漂浮)．
