You never know how much difficulty we had ______the problem. Luckily, we managed to solve it with Mrs Wu’s help.
It takes _____one hour _____my homework every day.
Bob can play ________ tennis but can’t play ________ violin.
—Could you tell me the way to the nearest KFC? —Sorry, I don’t know, _______.
Sir, you should__________ at the red light.--------Do you remember?
Sally took a photo of her friends while they computer games.