slot and key

例句：

1. 1.The machine has a large slot for thebolts to go through.
   这台机器有一个大槽，螺栓可以穿过。
2. 2. Thecar had a small slot in the doorwhere you could put your phone.
   这辆车的门上有一个小槽，你可以把手机放进去。
3. 3. Thebook has a lot of pageswith different slots for notes and drawings.
   这本书有很多页，每一页都有不同的地方用来做笔记和画画。