---Has Tom finished his homework?---I don’t know. But he _________ it the whole morning.
-- It’s dangerous to walk across the street carelessly. --You’re right. We can’t be ________ careful while crossing the street.
If we don’t study hard, we will in our class.
I don’t know if she ____________ if it _____________ tomorrow.
How much difficulty did you have ________________ this problem?
Nanjing is _______ capital of Jiangsu and it is _______ city with many places of interest.