He tried his best to solve the problem difficult it was.A. howeverB. no matterC. whateve

问题补充：

He tried his best to solve the problem, difficult it was.

A. however

B. no matter

C. whatever

D. although

答案：

(答案→)A. however

B. no matter

C. whatever

D. although

解析：四个选项分别表示然而可是、不论怎样、无论什么和尽管，根据题意选A，他尽了最大努力解决问题，可是困难依旧。

如果觉得《He tried his best to solve the problem difficult it was.A. howeverB. no matterC. whateve》对你有帮助，请点赞、收藏，并留下你的观点哦！