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为了将放置在水平地面上、重G=100N的重物提升到高处.小明同学设计了如图(甲)所示的滑轮组装置.当小明用图(乙)所示随时间变化的竖直向下拉力F拉绳时,重物的速度υ和上升的高度h随时间t变化的关系图象分别如图(丙)和(丁)所示.若重物与地面的接触面积S=5×10﹣2m2,动滑轮重为20N,不计摩擦,绳对滑轮的拉力方向均可看成在竖直方向.求:

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    John graduated from a key university and he was very good at his major. He wished to find a good job. One day, he went to a company to 1 for a job. He got the news in a newspaper. He did some research on this company. When he was 2 everything went well. The manager asked him some questions and he answered them 3 John was very satisfied with his performance and was very 4that he could get the job. But at that moment, the manager's phone5 He picked up the phone, listened and nodded. And then he turned around and said to John, “Sorry, I want to get some important 6 now. Please give me the book with the red7on that desk.” John looked around and found 3 books on the desk, so John went to the desk, took one book and handed it to him 8Holding the book, the manager 9 the phone and said, “Sorry, we cannot give the job to you.” John was10and wondered why. The manager said, “There are three11 First, when you came into the office room, I found that the third button on your shirt had been missing. Second, there are three books with red covers on that desk, but you didn't ask me which one I needed and you took one 12 Third, I was answering the call. You should 13to the desk to save time. These 14showed you are not a careful person.” Therefore, John didn't get the job.

    We can learn a(n) 15 from John's experience. Some people don't 16 the details in our life. But it is the details that17Not only should we value what we learn but also we should pay more attention to the details. Sometimes they can even18our success or failure. We should form the habit of being careful and learn to keep the19between quantity and quality. We should keep in mind that 20comes first, without which quantity is of no significance.