Due to the shape of the（），whereby forward- and aft ship are differently shaped，a trim correction on the draft measurement has to be done.

A.incoming data
B.working data
C.outgoing data
D.new data

A.Filter masks with a combination filter should be brought and used whenever necessary
B.Only explosion-proof equipment（marked EEx）should be used
C.Avoid breathing petroleum gases，especially if they come from sour crude（smell of rotten eggs）
D.so far as possible，take early and substantial action to keep well clear