Except for coarse earthen-wares, which can be made from clay as it is found in the earth, pottery is made from special clays plus other materials mixed to achieve the desired results.
【单选题】读零件图,回答问题。 1. 在尺寸φ15H8中:φ15表示( ),H表示( ),8表示( )? A. 公称直径;孔的公差带代号;公差值 B. 直径尺寸;轴的公差带代号;公差等级 C. 公称尺寸;基本偏差代号;公差等级 2. 该零件表面粗糙度要求最高的表面是( ),其Ra值是( )? D. φ27f7圆柱面 ;Ra6.3 E.零件左端面;Ra1.6 3.图中未注倒角是( )? F. C2 ...