下列属于取代反应的是
A.甲烷燃烧
B.在镍催化下,苯与氢气反应生成环己烷
C.乙烯使溴水褪色
D.光照条件下甲烷与氯气反应生成一氯甲烷
答案:D
A为氧化反应;B、C为加成反应
根据句意和首字母提示完成下列句子。
1. — How's it going?
— Not b_____.
2. T_____! It's windy all day. I can't go out to play ping-pong.
3. It's snowing. It's p_____ cold today.
4. How's the w_____ in Boston?
5. S_____ hard and do better every day.
新形势下党的建设有何新要求?