A.≤0.1/1000B.≤0.2/1000C.≤0.5/1000D.≤0.8/1000
A.指針B.小球最低點(diǎn)C.球中心D.小球最高點(diǎn)
A.腐蝕1/3B.腐蝕1/2C.腐蝕1/4D.腐蝕1/5