Experts are trying to work out a plan to
题型:选择题
问题:
Experts are trying to work out a plan to deal with the problems caused by global warming________
it is too late.[ ]
A. when
B. if
C. before
D. until
Experts are trying to work out a plan to deal with the problems caused by global warming________
it is too late.[ ]
A. when
B. if
C. before
D. until