The depth over a shallow patch，（）about

1、A shallow dish positioned at the norma

A shallow dish positioned at the normal water level is connected to the（）This enables the blowing down or removal of scum and impurities from the water surface.Amain stern stop valveBauxiliary steam stop valveCscum valveDblow down valve

2、A device fitted over the discharge ope

A device fitted over the discharge opening on a relief valve consisting of one or two woven wire fabrics is called a flame（）.AstopperBscreenCfilterDrestrictor

3、The depth（）a shallow patch，lying about

The depth（）a shallow patch，lying about 1.3 miles southeastward of Nanshan Tou lighthouse reduces to about 6.1 meters.AaboveBoverCupDupo

4、The company has（）over the years into a

The company has（）over the years into a multi-million dollar organization.AinvolvedBresolvedCevolvedDrevolved

5、Over a third of the population was est

Over a third of the population was estimated（）(无法获得) to the health service.

6、（）refers to the depth of a vessel belo

（）refers to the depth of a vessel below the waterline，measured vertically to the lowest part of the hull，propellers or other reference points.AFree boardBStability heightCMetacentric heightDDraft