国家标准GB/T 1800.2-1998规定,标准公差分为18级。()
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When bilge water is heated in a holding tank, which one of the following statements is not
A. The high temperature facilitates primary gravity separation
B. Most of the oil and organic solvents are raised to the top layer
C. The high the temperature is, the more the top oil will be collected
D. The high temperature has little use on the separation of emulsified oil
为提高刚度和抗振性,有的机床主轴采用三个支承,一般这三个支承可以都是主要支承。()
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