题目

Look! These red shorts are ________ sale ________ only $ 8. A . on; at B . on; for C . at; for D . for; on 答案：B18．下列有机物不能通过加成反应制取的是（　　）A．CH3CH2ClB．CH2Cl-CH2ClC．CH3-CH2OHD．CH3 Cl