单项选择题
A. chief officer B. captain C. bosun D. second officer
Cleaning is a constant job （）board a ship.A.atB.onC.for...
单项选择题Cleaning is a constant job （）board a ship.
A.at B.on C.for D.with
Cleaning is a frequent （）on board a ship.A.dutyB.respon...
单项选择题Cleaning is a frequent （）on board a ship.
A.duty B.responsibility C.job D.work
Please return it after （）it.A.useB.usedC.usingD.to use
单项选择题Please return it after （）it.
A.use B.used C.using D.to use
