我怀疑有人一直在窃听我们的私人讨论。

I suspect someone has been ___listening ___in on our private discussions.

她决定窃听同事们的对话。

She decided to ___listen ___in on her colleagues' conversations.

当局有时可以窃听可疑的通讯。

Authorities can sometimes ___listen ___in on suspicious communications.