适宜餐前0.5小时服用的降糖药是（）
A．阿卡波糖
B．罗格列酮
C．格列本脲
D．格列美脲
E．二甲双胍
参考答案：C
It's impossible for a child to do so much work within a short period of time, ______
A. isn't it B. is itC. has it D. hasn't it
企业以商业汇票采购物资，汇票到期时如遇到资金困难无力付款，只能转为应付账款。( )
