Jack ________ to the manager for the mistakes he had made. A. excused B. pardoned C. forgave D. apologized 答案:D给出下列命题:
①若平面α内的直线l垂直于平面β内的任意直线,则α⊥β;
②若平面α内的任一直线都平行于平面β,则α∥β;
③若平面α垂直于平面β,直线l在平面α内,则l⊥β;
④若平面α平行于平面β,直线l在平面α内,则l∥β.
其中正确命题的个数是( )
A.4 B.3 C.2 D.1