题目

— When will Joe come here again? — Next Tuesday or Wednesday. It's up ________ him. A . on B . for C . to D . with 答案：C如果，分析甲乙两物体的速度v甲，v乙,则有（　　　　） A、v甲＞v乙       B、v甲＜v乙 C、v甲＝v乙        D、无法判断