题目

High-speed trains are seen as one of the new Four Great of China.A. Achievements B. Agreements C. Environments D. Instruments 答案：【答案】A【解析】句意：高速列车被视为中国四大新成就之一。A. Achievements成就；B. Agreements同意；C. Environments环境；D. Instruments仪器。根据High-speed trains可知这里是说成就。根据题意，故选A。如图，三角形ABC的两个顶点B、C在圆上，顶点A在圆外，AB、AC分别交圆于E、D两点，连结EC、BD． (1)求证：ΔABD∽ΔACE； (2)若ΔBEC与ΔBDC的面积相等，试判定三角形ABC的形状．