You ______ the experiment twice, not once.
题型:单项选择题
问题:
You ______ the experiment twice, not once.
A.should have carried out
B.shouldn't have carried out
C.haven't carried out
D.couldn't have carried out
You ______ the experiment twice, not once.
A.should have carried out
B.shouldn't have carried out
C.haven't carried out
D.couldn't have carried out