If I ______ about this computer program, a hage amount of time and energy would have been saved.
#87162
A
know
B
knew
C
had known
D
have known
推荐题目
If human beings had been a bit less greedy and cruel, more birds and animals _______dying out.
#89245
A
ought to avoid
B
could have been avoided
C
should have avoided
D
might have avoided
If people ______virtual reality holidays, we ______ on an around-the-world tour．
#87555
A
invent; go
B
invented; had gone
C
invent; have gone
D
invented; would go