题目

－ What do you think made the woman so upset?       －________ weight. A. As she put on     B. Put on     C. Putting on     D. Because of putting on 答案：C正四棱锥S-ABCD中，O为顶点在底面上的射影，P为侧棱SD的中点，且SO=OD，则直线BC与平面PAC所成的角是 ______．