把硬币放进投币口。

Put the coin in the ___slot.

不是插入硬币，而是把卡插入槽中，然后拨号。

Instead of inserting a coin, you put your card in a ___slot and then dial the number.

停车计时器有一个投币口，用于支付停车费。

The parking meter has a ___slot for coins to pay for your ticket.