有一种用来测量绳中张力的仪表，图中B，C为夹在绳上夹子的横截面，测量时，只要用如图所示的一硬杆竖直向上作用在绳上的某点A，使绳产生一个微小偏移量a，借助仪表很容易测出这时绳对硬杆的压力F。现测得该微小偏移量a=3 mm，BC间的距离为2L=400 mm，绳对硬杆的压力为F=150 N，则此时绳中的张力FT约为
A.5×103 N
B.1.0×104 N
C.2.5×103 N
D.1.5×104 N
答案：A
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| One day a famous speaker gave a speech to a crowd of people. He held up a 20-dollar bill. He asked, "Who would like this $20 bill" Hands were raised. Then he said,"I am going to give this $20 to one of you, but first let me do this." He began to crumple (弄皱) the 1 . He then asked the audience (观众), "Anybody still wants it?" Still the hands went 2 in the air. "What if I do this?" He asked, and he 3 it on the ground, and started to step on it. He 4 it up. Now the bill was 5 and crumpled. "Now who still wants it?" Still the hands went up. "My friends," He continued, "You have all learned a good lesson. No matter 6 I did to the money, you still wanted it because the bill did not lose its 7 . It was still worth $20. Many times in our 8 , we are dropped, crumpled, and stepped on, because we sometimes 9 wrong decisions, or we may 10 with something we do not 11 . When that happens, we feel depressed and think we are 12 . But in fact no matter what has happened or what will happen, you will never lose your value. The worth of our life comes not 13 what we do or whom we know, but in who we are! Don't forget 'the worth of a thing does not depend on its outside 14 , but on its inner value.' This is the 15 of life. | ||||
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