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 （）.

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。

配位多面体相联的最稳定形式是（）

配位多面体

当配位多面体为八面体时，正负离子半径比为（）。

什么是配位数？什么是配位多面体？晶体结构中可以看成是由配位多面体连接而成的结构体系，也可以看成是由晶胞堆垛而成的结构体系，那么，配位多面体与晶胞怎么区分？

当配位多面体为四面体时，正负离子半径比为：（）

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。