问题
Do you know mother giant pandas have only one or two babies ______ ? — Sorry, I don’t know. [ ]
A: at a time
B: at time
C: at times
D:at that time
B: at time
C: at times
D:at that time
正确答案是：
同类题型
I want to borrow a book ______ animals. [ ]
Is the Youth Center open to the public yet?—Yes. It ______ for almost one and a half years.
What do you spend your time on ___ work and study? [ ]
Tom is my friend. I’m in Class Three with ______ .
There _______ a bank , two supermarkets and a park in the neighborhood.