theory

Charles Darwin's theory of evolution explains how species change over many generations through natural selection.

(Chinese) 查尔斯·达尔文的进化论解释了物种是如何通过自然选择历经多代发生变化的。

The Big Bang theory is the leading scientific explanation for how the universe began.

(Chinese) 大爆炸理论是关于宇宙如何起源的主要科学解释。