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（）.

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。

1929年意大利的（）教授正式开设农业生态学课程并正式出版农业生态学一书。

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。

信号流图（signal flow diagram）

Compensated flow control or constant flow valves are used in hydraulic systems to（）

流（Flow）

养分流 nutrient flow

Under centrifugal pumps are the volute, diffuser, mixed-flow, axial flow and （） or regenerative types.