选择：thank you for the great trouble you have taken---me with

选B,做题要仔细,这样你就能把题看清楚.
这里其实只是把great trouble提前了而已,还原一下,就很简单了．
take trouble to do sth考察的就是这个词组,意思是不辞辛苦．
感谢你不辞辛苦帮我学英语．
have trouble (in) doing sth
take trouble to do sth
两个是不一样的,如还有不明白,可以查字典．