题目

We have T-shirts ________ green for only $ 8. A . at B . in C . on D . With 答案：B已知△ABC和△A′B′C′相似，△A′B′C′的面积6cm2，△A′B′C′的周长是△ABC的周长一半．AB=8cm，则AB边上的高等于（   ）     A．3cmB．6cmC．9cmD．12cm