题目

Luggage     We ask you to keep a medium – sized suitcase per person, but a small holdall can also be taken onto the coach. Seats Requests for particular seats can be made on most coach breaks（巴士旅游）when booking, but since seats are booked on a first come, first serve basic, early booking is advisable. When bookings are made with us, you will be offered the best seats that are available on the coach at that time.Travel Documents  When you have paid your deposit(订金) we will send you all the necessary documents, so that you receive them in good time before the coach br如图，是一对变量满足的函数关系的图象，有下列3个不同的问题情境：①小明骑车以400米/分的速度匀速骑了5分，在原地休息了4分，然后以500米/分的速度匀速骑回出发地，设时间为x分，离出发地的距离为y千米；②有一个容积为6升的开口空桶，小亮以1.2升/分的速度匀速向这个空桶注水，注5分后停止，等4分后，再以2升/分的速度匀速倒空桶中的水，设时间为x分，桶内的水量为y升；③矩形ABCD中，AB=4，BC=3，动点P从点A出发，依次沿对角线AC、边CD、边DA运动至点A停止，设点P的运动路程为x，当点P与点A不重合时，y=S△ABP；当点P与点A重合时，y=0．其中，符合图中所示函数关系的问题情境的个数为（ ）A．0B．1C．2D．3