问题
单项选择题
It's impossible for a child to do so much work within a short period of time, ______
A. isn't it
B. is it
C. has it
D. hasn't it
答案
参考答案:A
It's impossible for a child to do so much work within a short period of time, ______
A. isn't it
B. is it
C. has it
D. hasn't it
参考答案:A