This paper compares the similarities and differences between Grignard reagent and reformatsky reagent from two aspects,which are preparation and reactivity,and analyses the reasons that cause differences from the two reagents' structures.

The paper compare the similarities and differences by the ways of studying such as the combination of the dynamic and static ways, the macroscopic and microscopic ways.

From the function,principal and application,this article makes analysis of similarity and difference between fire and invading inspection system.

The similarity and difference between the infant industry protecting theory and the strategic trade policy theory are discussed.

This article proves the differences and similarities of contradiction movement of cognition itself with the viewpoint of materialism and idealism in many respects and draws dististinctions in accordance with the theory of both and extends the way of researching the movement of cognition itself.