小测验：选择正确的单词

1. egg timer
   n. 煮蛋计时器
   

1. The self-timer is sometimes very useful.
   有时候定时装置很有用。
2. A self - timer is installed in this camera.
   这架相机有自动装置。
3. We employ part - timer to make up for staff shortage.
   我们雇佣临时工以弥补人员不足(短缺)。
4. The permanent staff and part - timer.
   固定职员和临时工
5. The oven has an automatic timer and other refinements.
   这个烤箱有自动定时器及其他改进装置.

　3个名词解释