流饱压差定义为井底流压与（）之差。

A、原始地层压力

B、目前地层压力

C、原始饱和压力

D、井口流压

If you have to jump in the water when abandoning a vessel，your legs should be（）.

A.spread apart as far as possible

B.held as tightly against your chest as possible

C.in a kneeling position

D.extended straight down and crossed at the ankles