Cribbing is（）.

A.wooden blocks or dunnage placed between a deck load and the deck

B.the chains and shackles used to secure a deck cargo

C.a crate in which a deck cargo is packaged

D.cardboard separation pieces placed between deck loads to prevent chafing

将E-R图转换为关系模式时，实体和联系都可以表示为（）。

A．属性

B．键

C．关系

D．域