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
Jack does his homework ________ Mary. So they both always get good grades in the exams.
#57427
A
so careful as
B
as carefully as
C
so carefully as
D
as careful as
David likes vegetables, _________ tomatoes, potatoes and cabbages. 
#56099
A
of course
B
for example
C
and so on
D
such as
—Why do you like staying in Guiyang?—Because the weather there is _____ too hot _____ too cold.
#58356
A
either; or
B
neither; nor
C
both, and
D
not only; but also