There are not many core concepts in each subject,but they are very important.The core concept is important in that it could be transferred.Therefore,students could think go beyond the topics and facts.For instance,if students understand the essence of war,not only can they understand how the war occurs,how to avoid the war,but also bring them the methods of analyzing wars in the past and the future,even how to look on the conflicts in our daily life which can be viewed as “Micro-wars”.