While we _________, we saw a UFO land on a street. 
#41211
A
were shopping
B
shopped
C
are shopping
D
shop
推荐题目
It was said            was how the Chinese first raised silk worms.
#72116
A
that what
B
that which
C
that who
D
that that
All the students went to see ______ with her.
#71958
A
what the matter was
B
what was the matter
C
what wrong was  
D
what was the wrong
You will be late for school ________you hurry up.
#68226
A
if
B
since
C
when
D
Unless