题目

            is reported in the newspaper is that seventeen climbers have been killed in the snow tsunami(雪崩).      A. It        B. As      C. What      D. That    答案：C如图，已知梯形ABCD中，AD∥BC，BC=3AD，E是腰AB上的一点，连接CE，（1）如果CE⊥AB，AB=CD，BE=3AE，求∠B的度数；（2）设△BCE和四边形AECD的面积分别为S1和S2，且2S1=3S2，试求的值．