he couldn't persuade her to change her mind,no matter how hard he ___ try

问题描述:

he couldn't persuade her to change her mind,no matter how hard he ___ try
a might b could
选A 为何B不可?

不论他怎么尝试,他都不肯能说服她改变主意的
这里之所以用might,根据意思理解,他其实还没有去做,并不是能力的问题,在这里只是表示假设