The word "discharge" as used in Pollution Prevention Regulations applies to oil （）. leaked into navigable waters。 poured into navigable waters。 pumped into navigable waters through a fixed piping system。 all of the above。
空调系统的组成是什么？
What is NOT a securing system used on a containership?（）. Lashing system。 Stacking system。 Locking system。 Buttress system。
What purpose does a bridge fitting serve when lashing containers?（）. Ties a container stack to the deck。 Ties a container to the container below it。 Restrains racking loads。 Restrains the container against horizontal motio。
用厚度2mm的铝板大批量焊接重要结构件，最合适的焊接方法是（） 钎焊。 氩弧焊。 气焊。 手弧焊。
设立认证机构，应当符合的条件有（）
