Air pollution has become__________ than ever before. We must do something to stop it.

---I’m getting fatter and fatter. What should I do, doctor? ---You should eat ______ food and take ______exercise.

Mike is _____ than his friend Sam.

－Hi, Tom, which is the          street in your city ?－High Street. Many people go shopping there.

Sally is ________ of the twin sisters (双胞胎姐妹) .