凡强度等级为（）及以上的混凝土为高强度混凝土

高强砼：强度等级为C50及其以上的混凝土。

强度等级为100及其以上的混凝土属于（）。

当混凝土强度等级为C60及以上时，水泥强度等级为混凝土设计强度等级的比值应小于（）。

混凝土组成材料中一般以水泥强度等级为混凝土强度等级的（ ）倍为宜。

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。