简述确定结构地震作用的底部剪力法和振型分解反应谱法的基本原理和步骤？ 

试述革兰氏染色反应的原理和步骤。

试述植物病毒的鉴定原理和方法。

试述裸子植物和被子植物的基本特征。

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.

枯草杆菌不管是革兰氏染色，还是鞭毛染色，其菌体形态大小不变。

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。

试述植物组织培养的原理和特点

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。

革兰氏染色反应的成败关键是什么？为什么革兰氏染色有十分重要的理论与实践意义？