下列估测值中，最接近实际的是（ ）
A．人正常步行的平均速度是10m/s
B．中学生跑100m约需8s
C．适合人们洗澡的热水温度约为70℃
D．中学生正常的脉搏约为70次/分
A、人正常步行的平均速度是1m/s，故A不符合实际；
B、中学生跑100m约需11s，故B不符合实际；
C、适合人们洗澡的热水温度约为40℃，故C不符合实际；
D、中学生正常的脉搏约为70次/分，符合实际．
故选D．
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| When I entered Berkeley, I hoped to earn a scholarship. Having been a Straight-A student, I believed I could 1 tough subjects and really learn something. One such course was World Literature given by Professor Jayne. I was extremely interested in the ideas he 2 in class. When I took the first exam, I was 3 to find a 77, C-plus, on my test paper, 4 English was my best subject. I went to Professor Jayne, who listened to my arguments but remained 5 . I decided to try harder, although I didn't know what that 6 because school had always been easy for me. I read the books more carefully, but got another 77. Again, I 7 with Professor Jayne. Again, he listened patiently but wouldn't change his 8 . One more test before the final exam. One more 9 to improve my grade. So I redoubled my efforts and, for the first time, 10 the meaning of the word "thorough". But my 11 did no good and everything 12 as before. The last hurdle was the final. No matter what 13 I got, it wouldn't cancel three C-pluses. I might as well kiss the 14 goodbye. I stopped working hard. I felt I knew the course material as well as I ever would. The night before the final, I even 15 myself to a movie. The next day I decided for once I'd have 16 with a test. A week later, I was surprised to find I got an A. I hurried into Professor Jayne's office. He 17 to be expecting me, "If I gave you the A as you 18 , you wouldn't continue to work as hard." I stared at him, 19 that his analysis and strategy were correct, I had worked my head 20 , as I had never done before. I was speechless, when my course grade arrived: A-plus. It was the only A-plus given. The next year I received my scholarship. I've always remembered Professor Jayne's lesson: You alone must set your own standard of excellence. | ||||
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