At first, I didn’t know what Facebook was, and now I do know what it is. I have to say, it

At first, I didn’t know what Facebook was, and now I do know what it is. I have to say, it sounds like huge waste of time.
A. /, the
B. /,a
C. the, a
D. a, the

A. /, the(答案→)B. /,aC. the, aD. a, the解析：考查冠词：句意：一开始，我不知道Facebook是什么，现在我知道它是怎么回事了，我不得不说，这听起来象浪费时间。第一空Facebook前面不加冠词，第二空是词组a waste of time浪费时间，选B。

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