—The charity walk begins _______ 9.00 a.m. Don’t be late. —No problem.
At that moment I had no choice but _____________ the policeman for help.
I’m very worried because I have made ________________ progress in my math.
You never know how much difficulty we had _________________ the problem. Luckily, we try to solve it with Mrs Wu’s help.
--- How hard-working the teachers are!--- I agree with you. The teachers are always strict __________us.
The film has ___________ for half an hour. Shall we give it up?