把钥匙插入锁槽就能开门。

Insert the key into the ___slot to open the door.

我们预约了下午两点的就诊时段。

We reserved the 2 PM ___slot for the doctor's appointment.

我预约到了周五下午三点的时间段。

I got a ___slot at 3 PM on Friday afternoon.

她把硬币塞进了老虎机的投币口。

She inserted a coin into the ___slot of the casino machine.