【正文】
re ____________ some tall buildings now. 3. I _____________ listening to music now. 4. They ___________ not at school yesterday. 5. There ___________ some milk in the glass now. 五. 給問(wèn)句選出正確的答語(yǔ)。 ( )1. London is a big city ___________ dirty air. A. on B. for C. with ( )2. It ________ dirty before, but it _________ clean now.\