某同学用游标为20分度的卡尺测量一薄金属圆板的直径D，用螺旋测微器测量其厚度d，示数如图所示。由图可读出D=________cm，d=________cm。
5.080 0.3774-0.3778
题目分析：对于主尺最小分度为1mm，精确度是0.05mm的游标卡尺，主尺上的读数为50mm，游标卡尺上的第16条刻度线与主尺上某一条刻度线对齐，游标尺上的读数为0.80mm，，因此，薄金属圆板的直径D为50.80mm=5.080cm；对于螺旋测微器，固定刻度上的读数为3mm+0.5mm=3.5mm，可动刻度上的读数为(27.4～27.8)×0.01mm，所以薄金属圆板的厚度d为3.774～3.778mm。即0.3774-0.3778cm
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| Last week 1 was trying to cheer up Jimmy the Bike Boy. But 2 week, Jimmy is happy again. 3 Monday he told a radio interviewer that he had run out of 4 to buy old bikes. He also put up some 5 asking for old bikes and called up all his friends and told them about the problem. He even handed 6 advertisements at a local supermarket. Then he told the teachers at 7 about his problem and they set up a call-in center for parents. The strategies 8 he came up with worked out fine. He now 9 sixteen bikes to fix up and give away to 10 who don't have bikes. | ||||
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