一般来说，低级测量水准可变换为高级测量水准，而高级测量水准不能变换为低级测量水准。

国家控制网布设的原则是由高级到低级、分级布网、逐级控制。（）

井下测量可不遵循高级控制低级的原则。

下列测量方法中，可用于建立国家一二等高程控制网的方法包括（）

下列测量方法中，可用于建立国家一、二等高程控制网的方法包括（）。

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。