句型转换。

1.  I think the most helpful invention is the light bulb. (对画线部分提问)

     ______ do you think______the most helpful invention?

2.  I'd like to have a radio. (改为一般疑问句)

     ______you______ to have a radio?

3.  He wants to have a computer because he likes playing games.(对画线部分提问)

     ______ ______he______ to have a computer?

4.  We must repair the computer now. (改为被动语态)

     The computer______ ______ ______now.

5.  I often hear her sing in the next room. (改为被动语态)

     She______ often______ ______sing in the next room.

在深度为5的满二叉树中，叶子结点的个数为

A．32

B．31

C．16

D．15