问题

Cloning plants is straightforward cloninganimals is very complicated .

A:in case of
B:although
C:while
D:as if

正确答案是：

同类题型

I would have come sooner but I ________ that they were waiting

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Tell me about it-don’t _____ anything _____!

Tom! I forgot to bring my notebook this morning. — Don’t worry! I it for you.

What a pity!—Yes, I ____ his not trying it, but in vain