He met many problems------ he was going over his lessons.
#57608
A
before
B
as soon as
C
since
D
while
推荐题目
A tourist will easily lose his way in Shanghai_____ he has a map or a guide.
#56219
A
if
B
since
C
while
D
unless
__________he is ill, __________he goes to school.
#56079
A
Although, but
B
/, /
C
Although, /
D
But, although