题干
－If we take a plane, we'll of course have arrived in Paris by the next weekend. (皖南八校)
－Don't be sure, we should______the weather factor. What shall we do if it is foggy?
A：leave alone
B：allow for
C：look over
D：take advantage of
答案(点此获取答案解析）
B
，不等式 
恒成立，则 
的取值范围是（