有关资格预审和资格后审的阐述，正确的是( )。

A．一般情况下，进行资格预审的，一般不再进行资格后审

B．资格预审和资格后审的内容与标准不同

C．资格预审提高了招标人的采购成本

D．资格后审是指在定标后对投标人进行资格审查

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

A.the life raft 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