载波通信的传输介质是电力线，微波通信的传输介质是（），光纤通信的传输介质是光导纤维（光纤）。

光纤作为有线电视信号重要的传输介质，影响光纤通信系统传输距离和容量的最主要因素是（）。

单模光纤作为传输媒介，主要优点是：传输（）大，（）长。

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.

固定通信是指通信终端设备与网络设备之间主要通过电缆或光缆等线路固定连接起来而实现的用户间的相互通信，其主要特征是终端的（）或（）。

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。

（）用于腰部等受伤送院前急救护理的骨折处理，特别适用于群体现场急救。

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。