在城市桥梁工程中，目的是减轻结构自重，尽量减少施工对现况交通与周边环境的影响的桥梁结构是（ ）。

Every deliberate act of wrongdoing by the master or any of the crew against the ship or cargo，without the authorization or privity of the Shipowner or his agent，is（）.

（）, 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。

多孔桥梁跨径总长是指（）；拱轴线是指（）。

公路桥梁总长是指（）两个桥台侧墙尾端间的距离。

对于多跨桥梁总长小于500m的桥梁，其平面控制测量等级为（）

桥孔总长是指桥梁排水宽度，既桥梁各孔净跨度的总和。

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。