Start studying early and don’t study too much  .
#80937
A
at one time
B
at a time
C
at times
D
from time to time
推荐题目
Over the past decades , sea ice          in the Arctic as a result of global warming .
#84442
A
had decreased
B
decreased
C
has been decreasing
D
is decreasing .
28. I'm afraid we'll have to work extra hours for there are still some problems ________.
#81046
A
remaining to settle
B
remaining to be settled
C
remained to be settled
D
to remain to settle