利用时间数列进行预测的方法中，趋势外推法预测过程的主要步骤包括（）。

A.计算估计标准误差

B.对模型进行检验

C.求解模型参数

D.选择趋势模型

For a floating vessel,the center of the floating is the point in the waterpiane.（）.

A.aboat which the vessel lists and trims

B.which coincides with the center of buoyancy

C.which, in the absence of external forces, is always vertically aligned with the center of gravity

D.which is shown in the hydrostatic tables as VCB