题目

A、B两物体在同一直线上运动，t=0时它们在同一位置，它们的v-t图象如图所示，下列说法正确的是（ ）A.0到20s，A在B的前面，20～40s，B在A的前面B.20s末，A、B在同一位置，且A、B速度相等C.40s末，A、B在同一位置，A的速度大于B的速度D.0到40s，A、B之间的最大距离是50m 答案：【答案】D【解析】A．0到20s，B的速度较小，A在B的前面，20～40s内，B的速度较大，A仍在B的前面，直到40s末两者相遇，故A错误。B．在第20s末两物体速度相等，由图线的“面积”看出，这段时间内B的位移小于A的位移，A、B不在同一位置，故B错误。C．由图可知，40s末两者位移相等，相遇，此时A、B在同一 Last week, I had a wonderful summer camp with my classmates. We ______ at the bus station early in the morning. After saying ______ to our parents, we got on the bus. We ______ two hours arriving at the campground. When we got there, everyone got off the bus ______, laughing and shouting. We jumped and ran around the campground. It was the _____ time for us to be away from parents. So some of us began to feel homesick (想家的). ______, when the night party and dances began, the homesickness disappeared. The next day, we had a ______ of climbing a mountain. At first, we climbed quickly. But on the half way, we were so ______ that we would like to give up. Our teacher ______ cheering us on. We believed that we could do better than others. Finally, we did well and my team won the match. “______ is difficult in the world if you keep trying”, said our teacher. I also learnt a lot from the camp.1.A.left B.saw C.met D.got2.A.goodbye B.sorry C.yes D.hello3.A.took B.spent C.paid D.cost4.A.cheerfully B.bravely C.sadly D.warmly5.A.one B.first C.last D.finally6.A.And B.Or C.However D.So7.A.interest B.idea C.chance D.match8.A.tired B.excited C.happy D.active9.A.stopped B.kept C.enjoyed D.preferred10.A.Something B.Everything C.Nothing D.Anything