振动棒振捣混凝土时，振动棒振捣插点间距不应大于振动棒的作用半径的（）倍。

依据GB50666-2011，8.4.3，振动棒振捣混凝土时，振动棒振捣插点间距不应大于振动棒的作用半径的（）倍。

用振动棒振捣的混凝土施工分层厚度不得大于振动棒长度的2/3。

下列选项中，不属于混凝土振捣器按传递振动方式分类的是（）。

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.

When loading or discharging dry mud or cement，crew members should use goggles and（）.

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。