A：不可能事件
B：互斥但不对立事件
C：对立事件
D：以上答案都不对
have, at, like, usually， watch, homework, after, play, come
I have a friend. His name is Li Daming. He often gets up ____ six o'clock in the morning. He ____ breakfast at seven. He goes to school five days a week. After school，he ____ plays games for half an hour. Look! What is he doing？He is ____ basketball. In the evening he does his ____ and he likes listening to music. He often ____TV for half an hour____ he finishes his homework. He goes to bed at ten o'clock. Do you ____ him?
氧气的化学性质比较活泼，能支持燃烧．
（1）如何验证一瓶无色气体是氧气？
（2）写出实验室制氧气的反应原理．（写出一个即可）
在我国的吐鲁番盆地有“早穿皮袄午穿纱”的说法，这说明当地（ ）
