时效硬化会改变钢材的性能，将使钢材的（）提高，（）降低。

吊车梁和桥梁用钢，要注意选用韧性大，且时效敏感性大的钢材。（）

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。

钢材的时效敏感性

时效敏感性大的钢材，时效后（）改变大。

什么是钢材的时效现象？低碳钢的时效有哪两种？

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。