可增加冠心病的危险性的物质有（）

A.脂蛋白a

B.总胆固醇

C.乳糜微粒

D.甘油三酯

E.低密度脂蛋白

Prior to entering a davit-launched liferaft，you should make sure that（）.

A.the liferaft is well ventilated of excess carbon dioxide

B.all personnel have removed their life preservers to facilitate boarding

C.the door flap has been cut away and stowed inside the raft

D.All of the above