I was out of town at the time, so I don’t know exactly how it _______. 
#104951
A
was happening
B
happened
C
happens
D
has happened
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Large quantities of oil      in a place near my hometown recently. 
#102718
A
has discovered
B
have discovered
C
has been discovered
D
have been discovered
Helen ________ her keys in the office so she had to wait until her husband ______ home. 
#101502
A
has left; comes
B
left; had come
C
had left; came
D
had left; would come