—Guys,Iwasreallywornout!Ican'twalkanyfurther!—Weshouldh...

问题详情：

— Guys, I was really worn out! I can't walk any further!

— We should have a rest. We ________ the cave a whole day.

A. exploring　　  B. are exploring　   C. have been exploring　   D. explore

【回答】

C

知识点：动词时态与语态

题型：选择题