计算人口出生率、死亡率、迁入率、迁出率等指标，其基数是该时期的平均人口数。()

人口自然增加数是指（ ）A．当期的自然出生人口B．当期的出生人口C．当期平均出生人口减平均死亡人口D．当期出生人口减死亡人口

最低死亡率（minimun mortality，or ecological morality）

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。

婴儿死亡率（‰）到2030年目标到达到（）.

旧中国人口高死亡率的原因主要是（）。

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。