A shore is a piece of securing dunnage that（）.

A.runs from a low supporting level up to the cargo at an angle

B.is also known as a distance piece

C.is placed on the deck under the cargo to distribute its weight evently

D.is run horizontally from a support to the cargo

由过热水蒸气和干空气组成的空气称为（）

A.湿蒸汽

B.干饱和蒸汽

C.饱和空气

D.未饱和空气