题目

He argued ________ smoking，and insisted that it was ________ argument that smoking was harmful to health. A．for；beyond     B．against；over      C．for；over      D．against；beyond   答案：D  为了测量电线杆的高度AB，在离电线杆24米的C处，用1.20米的测角仪CD测得电线杆顶端B的仰角α=30°，求电线杆AB的高度．（结果精确到0.01米）