It is impolite to leave             the meeting finishes. 
#58508
A
after
B
before
C
until
D
while
推荐题目
____ he was very tired, he didn't stop to have a rest.
#56214
A
But
B
As
C
Because
D
Although
_______ she is ill, _______ she goes to school.
#57900
A
Although; /
B
Although; but
C
But; although
D
Because; /