A.3 B.2 C.5 D.8
A.中絲讀數(shù)0.8m B.上絲讀數(shù)0.8m C.下絲讀數(shù)0.8m D.上絲讀數(shù)0.7m
A.3.5 B.2.5 C.1.5 D.0.7