After you enter the Ohio River at Cairo，which span of the Illinois Central RR Bridge would you select to pass under? （）

单项选择题After you enter the Ohio River at Cairo，the Map shows that the deepest water under the Illinois Central RR Bridge would be found under which span? （）

A.Right Descending Bank span
B.Left Descending Bank span
C.Center span
D.Water is equal under all spans

单项选择题After the passage of a cold front the visibility（）.

A.does not change
B.improves rapidly
C.improves only slightly
D.becomes poor

单项选择题After the initial cleaning of flue gas in an inert gas system the gas is passed through what device for final cleaning?（）

A.Scrubber
B.Demister
C.Deck water seal
D.Final filter

单项选择题After sending a message describing the symptoms of an ill crew member，you receive a message containing the code MRL. This means “（）”.

A.Apply ice-cold compress and renew every 4 hours
B.Commence artificial respiration immediately
C.Give enema
D.Pass catheter into bladder

单项选择题After reporting a casualty to a mobile offshore drilling unit，which record must be retained on board? （）

A.Record of drafts
B.Hull reports
C.Anchor record
D.Machinery repair book