题目

实数 ， 在数轴上的位置如图所示，下列式子错误的是（ ） A . a＞b B . ＜ C . ab＞0 D . a+b＞0 答案：C When I met him the other day, it was the first time we ________ each other since we were at school． [　　] A．saw B．had seen C．were seeing D．have seen