He tried his best to solve the problem,______ difficult it wasA.however B.no matter C.whatever D.although请问答案是A,请问别的为什么不行?
问题描述：
He tried his best to solve the problem,______ difficult it was
A.however B.no matter C.whatever D.although
请问答案是A,请问别的为什么不行?
答
whatever后面加名词，相当于no matter what ，difficult是形容词
although后面不能用倒装，可以改成although it was difficult
no matter 后面需要加how
答
无论有多困难，不选A选哪个意思都不对
答
however = no matter how
句子意思是：无论这个问题有多难,他都尽力去解决它.
B选项差疑问词how
C选项= no matter what,疑问词不对
D后面要接句子,不能接形容词