居民阶梯电价将城乡居民每月用电量按照满足基本用电需求、正常合理用电需求和较高生活质量用电需求划分为（）档。
A.一
B.二
C.三
D.四
参考答案：C
根据句意，用括号内所给单词的适当形式填空。
1. They will lose __________ (they) if they go down that path.
2. Jack is a __________ (honest) boy. He often tells lies.
3. The food smells __________ (terrible) bad, you won't like it.
4. Are you pleased with these __________ (dance) performances?
5. We held a party to celebrate our father's __________ (forty) birthday yesterday.
谈判是人类交往行为中最广泛、最普遍的（）。
A.自然现象
B.经济现象
C.军事现象
D.社会现象
