根据半坡氏族和河姆渡氏族的情况，试述母系氏族公社的社会结构。

头脑风暴法是科学的调查方法，反头脑风暴法不是。（）

头脑风暴法是科学的调查方法，反头脑风暴法不是。

我国习惯上将旅游团队分为出境旅游团队、入境旅游团队和国内旅游团队

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。

父系氏族公社是由氏族公社向（）过渡的社会组织形式。这时的婚姻形态由对偶婚向（）过渡。

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。