当且仅当两个串的值相等，称两个串（）。

一个论证是归纳上强的，当且仅当，它是逻辑上正确的。（）

在逻辑方阵中，两个命题是蕴涵关系，当且仅当，它们同时满足的条件是（）。

在逻辑方阵中，两个命题是蕴涵关系，当且仅当，它们同时满足的条件是（）。

文法G产生的语言是无穷的，当且仅当文法是递归的。（ ）

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。