题目

两个平面α、β,下面条件中能判定α⊥β的是(    )A.α、β都与γ垂直B.α∥γ,β⊥γC.直线l、b分别在α、β内,且l⊥bD.直线l与b互相垂直,且l∥α,b∥β 答案：答案:B解析:A错,α、β相交且同时垂直于γ,C错,若l是α、β的交线,α、β不能垂直,D错,若l、b相交且满足条件,则α、β相交.故B正确. When you are physically ____ to weather changes, maybe it’s a sign that you’re getting aged.         A. flexible                B. attractive             C. sensitive             D. active