theory

爱因斯坦的相对论是现代物理学的基石。

Einstein's ___theory of relativity is a cornerstone of modern physics.

经济理论为理解市场原则提供了一个框架。

Economic ___theory provides a framework for understanding market principles.

博弈论在经济学和政治学中有许多应用。

Game ___theory has numerous applications in economics and political science.