（）用来确认电子商务活动中各自的身份，实现网上安全的信息交换与安全交易。

确定档案信息系统安全保护等级，一般来说，高行政级别单位的重要和敏感信息要多于低行政级别单位的重要和敏感信息。

络与信息安全事件可分为（）四个级别

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.

信息安全是电子商务安全问题的最终形式。

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。

________用来确认电子商务活动中各自的身份,实现网上安全的信息交换与安全交易。