问题详情:
Only after they had performed hundreds of experiments _____ in solving the problem.
A. did they succeed B. they succeeded C. had they succeeded D. they had succeeded
【回答】
A
知识点:倒装与省略
题型:选择题
问题详情:
Only after they had performed hundreds of experiments _____ in solving the problem.
A. did they succeed B. they succeeded C. had they succeeded D. they had succeeded
【回答】
A
知识点:倒装与省略
题型:选择题