题目

已知直线m∥n，点A在m上，点B、C、D在n上，且AB=4cm，AC=5cm，AD=6cm，则m与n之间的距离（ ） A . 等于5cm B . 等于6cm C . 等于4cm D . 小于或等于4cm 答案：D小题1:The sign on the left tells us that _______ . A. this is a place for us to swimB. it’s safe to swim in this placeC. swimming is not allowed here