(2013·四川省乐山一模)The pupils were playing games in the classroom ________ a gunman entered and began shooting wildly at them.
#30425
A
while
B
when
C
as
D
before
推荐题目
___ is the most useful invention?
#32091
A
Do you think which of these
B
Which of these you know
C
Which of these do you know
D
You know which of these
You shouldn’t have failed the job interview. Why didn’t you do ___ the expert suggested?
#31688
A
if
B
when
C
as
D
because
The customs office is your luggage is inspected when you enter or leave a country.
#32869
A
where
B
when
C
why
D
who