函数在某一点处的导数是一种无穷小比无穷小的极限。

平行投影中，若直线垂直于某一投影面，则在该投影面上的投影（）。

横截面上分布内力在某一点的集度称为该点的（）。

可以在（）阶段采用Make-or-buy决策分析。

Every deliberate act of wrongdoing by the master or any of the crew against the ship or cargo，without the authorization or privity of the Shipowner or his agent，is（）.

（）, or drum is used for hauling in or letting out the wires or ropes which will fasten the ship to the shore.

A salvor may be（）the whole or part of the payment due under Salvage Convention to the extent that the salvage operations have become necessary or more difficult because of fault or neglect on his part or if the salvor has been guilty of fraud or other dishonest conduct.

The （） is used for hauling in or letting out the wires or ropes.

Vessels must be（）valid certificate of nationality or certificated of registry or license.

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。

y在某点可微的含义是：（　　）。