单项选择题
A. it is scarce B. so scarce is it C. its scarcity D. scarcity of it
You'll run （）trouble if you don't take care.A. downB. a...
单项选择题You'll run （）trouble if you don't take care.
A. down B. at C. across D. into
（）the knowledge, he didn't know how to ask the way.A. K...
单项选择题（）the knowledge, he didn't know how to ask the way.
A. Knowing not B. Having not known C. Not knowing D. Not to know
If I heard, I（）A. would not be askingB. will not askC. ...
单项选择题If I heard, I（）
A. would not be asking B. will not ask C. did not ask D. wasn't be asking
