（）, 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。

科学家公认（）是未来人类最合适，最安全，最绿色，最理想的替代能源。

消能形式的选择应根据水头及单宽流量的大小、下游水深及其变幅、坝基地质、地形条件以及构纽布置情况等，经技术经济比较后选定。

拱坝对地形和地质条件的要求？

拱坝对地形、地质条件有哪些要求？

简述适宜建设拱坝的场地地形地质条件。

简述拱坝的特点，其要求的理想地形和理想地质是什么？

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。