问题

Shall we go out for a swim?—Sorry, I can’t. I ______ housework for my mother now.
A:am doing
B:is doing
C:are doing
D:did
B:is doing
C:are doing
D:did
正确答案是:
同类题型
More and more trees were cut down. _____, many animals are dying out. [ ]
Our life _________ greatly in the last ten years.
Ann’s home is about ten kilometers_________school.[ ]
How many times he abroad before? –Never.
Excuse me. Where is the bus stop, please?–I’m sorry. I don’t know the way, _______.