实施经腹输卵管结扎术的合适时间是（）

A.非孕妇女在月经干净后3～4日

B.人工流产术后 * * 流血停止时

C.正常产后3～7日

D.剖宫产术后3～4个月经周期后

E.以上都不是

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