Question

【题目】The boys followed the marks that they ______, until finally they found their way back to the campsite.

A. left B. have left

C. had left D. have been left

Answer 1

【答案】C

【解析】

试题分析：C；考查时态。过去完成指发生在过去之前，也就是过去的过去的动作。句意：男孩跟随着他们留下的记号，直到最后他们到了回到营地的路。Leave the marks是发生在follow the marks之前的，所以用过去完成时，故选C。