登高用的梯子，单面梯与地面夹角以（）为宜.

登高梯子为人字梯时，两梯夹角宜为（）度左右，并用限跨铁钩挂牢。

冬季登高作业时，要按规定穿戴劳保用具，梯子及走道要采取可靠的（）措施，防止滑倒和坠落。

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。

拉线锚板拉杆与地面的夹角宜为（）º。

活动梯子的竖立与地面的夹角以（）度为宜，在光滑及冰冻地面上应有防滑措施

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。