A.1mm B.2±0.5mm C.2mm D.0.5mm
A.15mm×15mm,10~15點(diǎn)接觸 B.20mm×20mm,15~20點(diǎn)接觸 C.25mm×25mm,20~25點(diǎn)接觸 D.30mm×30mm,25~30點(diǎn)接觸
A.1個(gè)月 B.2個(gè)月 C.3個(gè)月 D.4個(gè)月