A、B、C、D四个物体做直线运动，它们运动的x-t、v-t、a-t图象如_爱下问搜题

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问题选择题

A、B、C、D四个物体做直线运动，它们运动的x-t、v-t、a-t图象如图所示，已知物体在t=0时的速度均为零，其中0~4s内物体运动位移最大的是（）

答案

答案：C

题目分析：A图像说明物体在4s内的位移为1m，B图像说明物体在4s内的位移为0m，C图像是加速度与时间的关系，如果将其转化为速度与时间的关系，则其图像都在时间轴的上方，说明它的位移是最大的，D图像也是加速度与时间的关系，将其转化为速度与时间的图像，与B图像是类似的，故其位移也为零，可见，该题选C。

完形填空

My friends and I had just finished lunch at a hotel when it started to pour 1 . When it became lighter, I decided to get my car, which was 2 at my office three streets away.
My friends argued that I shouldn’t go, mainly because I was seven months pregnant then. I assured them that I’d be very 3 .
I walked out of the 4 and started making my way to the car. At the traffic junction, a van stopped and the passenger got off with an umbrella. Before I knew what was happening, he walked right beside me and told me he’d escort(护送) me to my 5 . I was very embarrassed and declined(辞谢), but he was very 6 .
During our 7 , he kept telling me to walk slower, as the ground was 8 . When we got to the car park, I 9 him and we parted ways. I did not get his 10 and may not even recognise him now. Did he 11 stop for me? I’ll never know.
So how did I pay it forward? I was at home when I 12 two Indian construction workers walking in the heavy rain. They were probably on their way to the construction 13 near my estate, which was a long walk in. I went out and passed them an umbrella. I told them they should take the umbrella and 14 it. They were very grateful and like me, probably wondered why a 15 was offering such kindness.

A．destination

名词解释

临时再保险