. —Why didn’t you response to their greeting?  —Sorry. I ______they ______ to me.
#102318
A
don’t realize; are waving
B
don’t realize; were waving
C
didn’t realize; were waving
D
didn’t realize; are waving
推荐题目
Look out! The train ________.
#99925
A
leaves
B
is leaving
C
has left
D
left
Our food supply _____. We’d better get some in case there’s ____ left.
#101949
A
is running out, none
B
has run out of, none
C
is using up, nothing
D
has used up, nothing
— Isn’t it hard to drive downtown to work? —Yeah, that’s why I ______ to work by train. 
#101418
A
have gone
B
have been going
C
was going 
D
will have gone
The manager was concerned to hear that two of his trusted workers _____.
#101325
A
are leaving
B
have left
C
were leaving
D
will leave