动词 listen in:

1. listen quietly, without contributing to the conversation

2. listen without the speaker's knowledge

Listenon氯化琥珀胆碱[肌松药]listenv.听；倾听；听从；听信n.听；倾听listen for an answer等着听回答listening vocabulary听力词汇listening J-Horner应答塞孔listening to symphony听交响乐listening instruction听力教学listening attentively倾听listen absentmindedly心不在焉地听着Listeners' Letter Boxlistening-only test只听试验listening-in device窃听器

1. Company is mainly engaged in wiretapping.
   公司主要从事监听。
2. Newly installed seismometers will listen for glacial earthquakes.
   新安装的地震仪将可监听冰河地震的声音。