我们在后院种了几棵苹果树。

We ___planted some apple trees in the backyard.

他在花园里种了几棵新树苗。

He ___planted some new saplings in the garden.

警方发现有人在会议室里偷偷放置了录音设备。

The police found that someone had ___planted a recording device in the meeting room.