环境问题词汇（pollution, recycle等） — 英语填空题

根据句意和汉语提示填写单词，每空一词：(1) Air ___ (污染) is a serious problem in many big cities, so we should ride bikes more often. (2) Don't throw away those bottles — we can ___ (回收利用) them to protect the environment. (3) Too much ___ (噪音) from the factory makes it hard for people nearby to sleep at night.