地球上适合生物生存的地方，科学家称其为____．它包括____的底部、____ 的大部和____的表面．其厚度约为20千米．

词汇：

同素异形体　 ____；氨　 ____．铝 ____；合金　 ____；氯气　 ____；reducing agent ____；amphoteric ____；oxidation ____；Silicon ____；acid rain ____

68＋5____75

48－6____40

连词成句。

①《安徒生童话》   我   读    喜欢

②山河   祖国    壮丽   的    多么

③节目  我们   了   欣赏   精彩的

阅读理解
    Tom and his father, Mr. Smith, always go out for a walk after supper every day. After that, he does his homework and watches TV for half an hour. Then he goes to bed. Now Tom and his father are taking a walk along the road. It begins to rain. Tom wants to run for home. But his father says very slowly, “Don't run. Isn't it raining in front of you?”