I don't know________ they have passed the exam.
---Could you please tell me________________?---Yes. There is one on Center Street.
Don’t ________too late, or you’ll be sleepy in class tomorrow.
---I didn’t hear you come in just now.--- That’s good. We tried ________ any noise, for you were sleeping.
---The air pollution is terrible.---It will be worse _______ we take action to protect the environment.
---Which magazine do you like better, Crazy Reading or Teen’s Space?---I like ______ of them. They are useful for English lessons.