An immersion suit must be equipped with a(n)（）.

A.percentage of frequency of wave heights
B.percentage of poor visibility conditions
C.sea surface temperatures
D.amounts of precipitation

A.the altitude above sea level
B.the season of the year
C.the latitude or distance from the equator
D.All of the above

A.serves as a sea painter
B.detaches automatically
C.is used to rig the boarding ladder
D.is cut immediately as it is of no further use