JM-A型密贴检查器动接点环打入静接点片的深度应不小于( )。[332010204]

JM-A型密贴检查器动接点环打入静接点片的深度应不小于( )。[332010204]

A.(A)3mm

B.(B)4mm

C.(C)5mm

D.(D)6mm

正确答案是B