单项选择题
The lashings of a stack of containers with interlocking fittings restrain the forces that cause（）.
A.toppling B.racking C.buckling D.crushing
单项选择题 The securing systems for containers were developed to prevent container movement during which ship motion?（）.
单项选择题 What is NOT a securing system used on a containership?（）.
单项选择题 What purpose does a bridge fitting serve when lashing containers?（）.
