Theboysfollowedthemarksthatthey
问题详情：
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
【回答】
C
知识点：过去完成时及其被动式
题型：选择题
问题详情：
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
【回答】
C
知识点：过去完成时及其被动式
题型：选择题
