题目

-- I knocked into a tree when I went to the station to meet my friend. -- I suppose you        too fast. A. drive           B. are driving          C. have driven          D. were driving 答案：D命题①过两腰中点的直线是等腰梯形的对称轴；   ②过上下两底的中点的直线是等腰梯形的对称轴；③直角梯形是轴对称图形；                 ④等腰梯形有3条对称轴；其中正确的命题有A.0个B.1个C.2个D.3个