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 （）.

（）are liable to be stoten, pilfered or may damaged due to improper handing or stowage.

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。

学前儿童注意发展的趋势（）注意的发生先于选择性注意的发生，无意注意的发生发展早于有意注意的发生发展。

注意的种类：不随意注意(无意注意)、随意注意(有意注意)、随意后注意(有意后注意)。(心理学)

引起和保持幼儿无意注意的条件有哪些？

学前教育心理学研究的核心是幼儿学习心理和幼儿

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。