分离提纯光敏色素并证明其有红光吸收型和远红光吸收型两种形式的学者是（）、（）、（）等。

HF中键的力常数约为9N/cm，请计算： （1）HF的振动吸收峰频率； （2）DF的振动吸收峰频率。

植物对养分的吸收是依靠水分吸收时由水分带入植物体内的。（）

植物吸收矿质元素与吸收水分机理相同。

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。

高等植物的叶绿素所含的色素是（）。

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。