订货周期定义为从客户发出订单、提出购买产品或服务的要求到收到所订购产品或服务所经过的时间，包括在客户收到订购货物所需经过时间内发生的所有相关活动。

The tentative cargo plan（）.

A.eliminates confusion with the final stowage plan

B.shows the approximate amount of cargo to be loaded in each hold

C.expedites the total operation

D.requires an unproportional number of gang hours of work to discharge the cargo