Is that helpful ________ us?
-I can't stop smoking, doctor.-For your health, I'm afraid you_______.
Learning_______ country's language is a better way knowing of_______ culture behind it.
- My family will go to Hainan to spend the winter holiday.- Oh, wonderful! _______.
She_______ the homework today. She may do it tomorrow.
He eats_______ sweet food, so he becomes_______ fat.