That was so serious a matter that I had no choice but ________ the police.a. to call in b. call in c. calling in d. called in
This passage has too many long sentences. I’m afraid they will be hard for most of the students. Could you help to _______ them?
The police are to ______ the traffic accident that we don’t know _____.
— The floor is dirty. — Yes. It _______ for two days.
My sister_____ Tony for ten years next year.
Do you know a concert _____ in our hometown next month?