Frank often wears a mask _____ he can keep fit in the foggy and hazy (霾) weather.
#55316
A
only if
B
until
C
so that
D
even though
推荐题目
Don’t leave your seat ________ all the papers have been collected by the teacher.
#55185
A
after
B
when
C
since
D
until
Mother keeps telling her son not to get off until the bus .
#55396
A
will stop
B
is going to stop
C
stopped
D
stops
John had to start work at an early age, ____ his family was very poor.
#56957
A
or
B
so
C
but
D
because
