水泥石遭侵蚀，主要是与水泥石中的水化产物水化铝酸钙有关。

水泥石中的钙矾是如何生成的？它起何作用？对水泥石是否有破坏作用？

水泥石的硬化程度越高，凝胶体含量越少，未水化的水泥颗粒和毛细孔含量越多，水泥石的强度越高。

水泥石受腐蚀的基本原因是水泥石中含有水化铝酸钙和 ___ 。

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。

掺活性混合材料的水泥抗碳化能力差的原因是由于水泥石中的（）