在物理学的学习中，在很多定律和现象中都能发现“反抗”这个关键词.“反抗”无处不在的根本原因，在于任何事物都是由正反两方面构成的矛盾统一体，事物稳定的状态是“矛”和“盾”平衡的结果，当平衡被打破时，矛盾就显现出来，其结果是抵抗状态变化的趋势，能量、动量或物质就在抵抗过程中发生转移．明白了这个普遍的道理，不仅能使学习更有效率和乐趣，也能体会到物理学的美妙和深刻含义．

In the study of physics,the keyword resistance can be found in many laws and phenomena. The fundamental reason for the ubiquity of resistance is that everything is a contradictory unity composed of positive and negative aspects. The stable state of things is the result of the balance between spear and shield. When the balance is disrupted,the contradiction becomes apparent and the result is that the trend of resisting state changes. Energy,momentum or matter undergoes transfer during the process of resistance. Understanding this universal principle not only makes learning more efficient and enjoyable,but also allows one to appreciate the beauty and profound meaning of physics.