Perce Blackborow and his panions stayed on Elephant Island for six months before rescue came, so they a lot of difficulties.
A. must go through
B. may go through
C. must have gone through
D. could have gone through
网友回答
A. must go through
B. may go through
(答案→)C. must have gone through
D. could have gone through
解析：考查情态动词。根据题意可知本句为对过去事情的推测，故用情态动词+ have done，根据句意可知must have done过去一定做某事，选C。