The approach was condemned by many as a _______from normal scientific method.

花匠手握如图所示的修枝剪刀把手的末端，便可以轻松地剪断树枝．这种修枝剪刀一般刀口短、手柄长，这是为了____．使用时，若在轴上加润滑油，则可以提高杠杆的____．

周末，小陈同学陪妈妈逛商场，看到右图的情景，向妈妈解释了产生这一情景的下列几种原因，其中合理的是

下列反应中既是氧化反应又是化合反应的是（   ）

_______ in his school that many of his fans want to get close to him.