While my mother________ some washing, I was making  a kite for Mary. 
#40261
A
did
B
was doing
C
is doing
D
does
推荐题目
–Did you go to Jack’s birthday party? -- No, I ________. 
#40040
A
am not invited
B
wasn’t invited
C
haven’t invited
D
didn’t invite
---Is that Jack speaking?  ---Sorry, he _______ in. He _______ back in half an hour.      
#41814
A
isn’t; will be
B
wasn’t; will
C
isn’t; is
D
wasn’t; was
What ________ you ________ at this time yesterday?
#37876
A
did, do
B
have, done
C
were, doing
D
are, doing