根据物质的物理性质确定用途的是 [ ]

A．氮气做灯泡的保护气

B．用铁做导热材料

C．汽油作燃料

D．镁作照明原料

句型转换。

1. She does her homework every night. (改为否定句)

She _____________ _____________ her homework every night.

2. Tom often has lunch at school.(改为一般疑问句)

_____________ Tom often _____________ lunch at school?

3. This is a new pencil box.   (改为复数句子).

  These _____________ new pencil _____________.

4. She wants to drink two glasses of water.(对划线部分提问)

  _____________ _____________ water does she want to drink?

5. Simon chats with his friends every day.   (用now改写句子)

  Simon _____________ _____________ with his friends now.