Personnel boarding a davit-launched liferaft from a ship should be checked to assure they are not in possession of or wearing（）.

A.oil stained shoes or clothing

B.sharp objects that may puncture or damage the liferaft

C.matches or cigarette lighters

D.drugs or paraphernalia not approved by a medical doctor

i5T5.2智能车床的尾台具有点动功能。