When he _______ us to go in, we _______ outside the exam room for over half an hour. A. let - are standing B. let - have stood C. let - had been standing D. let - have been standing
When he _______ us to go in, we _______ outside the exam room for over half an hour.
A. let - are standing
B. let - have stood
C. let - had been standing
D. let - have been standing