下列各图的物理情景中能突出反映利用反作用力的是（ ）
A．宇航员上月球时做铁锤与羽毛下落的实验
B．龟兔赛跑
C．绳一端系在陷入泥潭的卡车上，另一端系在大树上，人用力拉绳的中间把车拉出泥潭
D．坐在河中浮冰上的小孩向一边扔东西，浮冰向另一边河岸漂动
解；A、宇航员上月球时做铁锤与羽毛下落的实验，验证下落快慢与物体质量有无关系，故A错误
B、龟兔赛跑，比较运动的快慢，故B错误
C、绳一端系在陷入泥潭的卡车上，另一端系在大树上，人用力拉绳的中间把车拉出泥潭，利用较小的合力能产生较大的分力，故C错误
D、坐在河中浮冰上的小孩向一边扔东西，浮冰向另一边河岸漂动，利用东西给小孩的反作用力，故D正确
故选D．
阅读下面短文，从短文后各题所给的四个选项(A、B、C、D)中选出最佳选项。 Last week I went to a supermarket. After I 36 the bill and was passing through the door, the alarm suddenly started to ring. Suddenly, a young guard ran toward me and ordered me to 37 him. I felt so upset and 38 . He took me to a small room, but I was 39 frightened that I stopped at the door. Finding me 40 to enter the room, he shouted that I had to go into the room. He closed the door. I thought he was going to hurt me. Suddenly, a 41 voice said in my ear: “Take out the things you’ve stolen!” “I stole nothing.” I said. “Do as I tell you. If we find them, you’ll be in trouble.” “There is nothing.” I answered. “I didn’t take anything.” I said, taking everything out of my pockets and bag. 42 this point, a guard came in and asked a salesgirl to 43 me. 44 , they found nothing. But they didn’t believe that I hadn’t stolen anything. So the young guard ordered me to pass through the door alarm again. I was 45 when it rang again. I felt 46 and burst into tears. I didn’t know how to prove 47 I was innocent(清白的). They made me go into the small room again. “Take out the stolen things quickly, 48 we will dial 110.” They said. “OK, call the police. I’ m not afraid.” I said 49 . Suddenly, they 50 their tone. After a while, a salesgirl asked me to raise my feet. I did 51 she had told me. There was a label (标签) on the bottom of my shoe. That was it! That was the 52 thing that had brought me such great trouble. But it 53 my innocence. After that, they 54 to me in the small room, But they should have apologized 55 , shouldn’t they? A lot of people were there when I was taken away. What did they think of me?
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