We were swimming in the lake _______ suddenly it began to rain heavily.
#30962
A
when
B
while
C
until
D
before
推荐题目
I toured the Great Wall，I was deeply impressed with the beautiful scenery．
#29943
A
For the first time
B
At first
C
The first time
D
It was the first time
He didn't realize he had forgot his bag _____ the plane had taken off.
#79688
A
unless
B
until
C
if
D
or
His friends ignored his advice, ______ they knew it to be helpful.
#31788
A
as if
B
since
C
even if
D
so that