句型转换。

1. They are balls. (改为否定句)

    They _______ _______ balls.

2. The clock is on the wall. (就画线部分提问) 

    _______ _______ the clock?

3.These are computers in English. (就画线部分提问) 

   _______ _______ these in English?

4. I can see the baseball.  (改为一般疑问句) 

   _______ _______ see the baseball?

5. Mr Read is our English teacher. (就画线部分提问) 

   _______ _______ your English teacher?

物业管理是市场经济的产物，( )是市场经济的基本特征。

A．平等互利
B．公平
C．竞争
D．发展