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.

When loading or discharging dry mud or cement，crew members should use goggles and（）.

Effects which are dutiable or subject to prohibitions or restrictions should be declared in （）.

PI校正为相位滞后校正。

按校正装置Gc（s）的物理性质区分，又有相位超前（微分）校正，相位滞后（积分）校正，和相位滞后—超前（积分-微分）校正。

串联校正按校正环节Gc（s）的性质可分为：（）、相位超前校正、相位滞后校正（）

滞后校正装置可抑制噪声并改善稳态性能。（　　）是一种滞后校正装置。

滞后校正装置能抑制高频噪声，改善稳态性能，采用串联滞后校正时（　　）。[2016年真题]

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。