发电机频率f.磁极对数p.转速n之间的关系为。（）
A.n＝60p／f；
B.n＝60f／p；
C.f＝p／60n；
D.f＝60p／n。
参考答案：B
用所给词的正确形式填空。
1. My mother ______ (wash) clothes at 8:00 every evening.
2. Which do you like ______ (good), fish, meat or vegetable?
3. I did some _______ (write) at home yesterday.
4. The little girl asked her brother ______ (not cry) in front of his friends.
5. They (not watch) the football match, will they?
6. We need ______ (buy) some more food tonight.
7. This is a famous team (call) "Black Duck".
8. A: Were there any (woman)______ (singer) then?
B: Yes, there were.
关于下图，下列说法不正确的是
A．△E2是2mol HCl(g)的总键能
B．该反应的热化学方程式为：H2(g)+Cl2(g)＝2HCl(g)△H ＝－183KJ.mol-1
C．通常情况下H2与Cl2混和不会反应
D．该反应是一个吸热反应
