从总体上来看，电子商务系统是三层框架结构，底层是电子商务网络平台，中间是电子商务基础平台，而第三层就是各种各样的电子商务应用系统。

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。

智能变电站系统一般分为三层，分别是哪三层？

基础数据平台自底向上分为三层，分别是（）。

动态自组网系统架构分为三层，分别是（）。

气管管壁可分为三层，由内向外分别是（）.

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。