题目内容
千分尺又叫螺旋测微器，是一种精密的测量量具，测量精度为0.01mm
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卡钳可以代替钢板尺直接测量出工件的尺寸
划线基准的选择原则是尽可能使划线基准和设计基准一致，以消除不一致产生的积累误差。
划线分为平面划线和立体划线
The English ceremony of afternoon tea dates back to the 1840s. The tradition evolved out of the rituals and routines that surrounded tea drinking in Britain before that time. Tea was first introduced to England in the late 1650s, but for a long time, it was only consumed by the royal family and the aristocracy due to its high cost. The habit of having afternoon tea did not become established until almost 200 years later. In those days, the British ate only two daily meals: a large breakfast late in the morning and a late dinner around 8 o'clock in the evening. Anna, the 7th Duchess of Bedford, can be credited for creating the tradition of afternoon tea to soothe hunger pangs before supper. She invited friends to join her for an additional afternoon meal at four to five o'clock. The menu included tea and snacks such as dainty cakes and sandwiches. Fine porcelain (瓷器) was used to serve this minor feast. Afternoon tea soon became popular, and is now a symbol of the elegant British way of life. As novelist Henry James wrote, "There are few hours in life more agreeable than the hour dedicated to the ceremony known as afternoon tea."
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