表示用经验评定法确定的道面等级序号的英文字母是：（）.
A.X
B.Y
C.A
D.U
参考答案：D
测量上限大于150mm的外径千分尺可以只检测微头的示值误差。示值范围为25mm的其测微头示值误差不大于（）。
A.2mm
B.3mm
C.4mm
Quiet student ____he may be,he talks a lot about his favourite sport after class.
A if B as C since D when
