根据句意及首字母或汉语提示完成单词。

1. I have an alarm c______. It can wake me up (叫醒) every morning.

2. Look! Tom's books are on his______(桌子).

3. My ______ (数学) book is in the drawer.

4. Where's my ______(帽子)?

5. —What's behind the chair?

    —My v______ tape.

科学技术对经济结构的影响首先表现在三类产业的组成发生了变化。