One such meeting was being held on board a ship on day.
老师,on board a ship=on a ship board吗,还是on board=on a ship省略了都可以?
on board为介词+名词构成的习语。其意义之一是“在飞机/船/火车上”。比如:
Theplanehad 125passengersandcrewonboard.
on board还可以作为短语介词,后接名词(飞机、船或火车)。比如:
Acustomsofficercame onboardtheship.