环境问题描述 — 英语词汇题

词汇填空：根据中文提示补全句子，每空一词。 1. Look! Smoke from the factory makes the air very d____ (脏的). 2. We should put r____ (垃圾) in the bin to keep the street clean. 3. Cars and buses make the city n____ (吵闹的) too. 4. To keep our city clean, we can take the bus or w____ (步行) to school.