【题目】—So are you saying that some scientists don’t believe in the greenhouse effect?
—No，I wouldn’t go that far.In fact，without the greenhouse effect the planet frozen.
A. has been B. would be
C. will be D. would have been
在线课程【答案】B
【解析】从答句中的“without the greenhouse effect”可知，此处是含蓄条件句，表示对现在事实的虚拟，所以选B。