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。

当市场均衡时，消费者剩余和生产者剩余相等。

简述消费者剩余和生产者剩余的含义以及对经济分析的意义？

从效率的标准来判断，垄断厂商的问题不在于减少了消费者剩余（消费者福利的测度），而在于所减少的消费者剩余没有全部转化成生产者剩余（生产者利润），有一部分白白浪费了。

区分消费者剩余和生产者剩余。这两个概念与国家经济福利有什么关系？

画出一个进口国的供求图。在允许贸易之前，消费者和生产者剩余是多少？有自由贸易时，消费者和生产者剩余是什么？总剩余有什么变化？

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。