1．(2019·全国卷Ⅰ)Further up, the weather changes — low clouds envelop the mountainsides, which are covered with thick grass. 包裹；包围
2．(2019·北京卷)Armed with this knowledge, they're able to carry out individually targeted campaigns to cheat people. 以……为目标
3．(2018·天津卷)If a smoke detector sets off an alarm and there is no fire or smoke, inform your hall staff. 警报器
4．(2018·天津卷)I asked them what they'd seen. “Oh, a few birds，” they said. They seemed bent on their destinations. 专心的
