单项选择题
When the truck does not work, the driver should（）engines.
A.turn on B.turn off C.shut up D.close
单项选择题 When the vessel arrives, the cargo of machinery to be unloaded is（）.
单项选择题 When working with lumber, wire and staples are not desirable to be used because（）.
单项选择题 Which is the summer load waterline on the load waterline mark?（）.
