保持饥饿，保持愚蠢，但也要保持年轻。
The present is a point just passed.
The study of mental processes requires both experimental and comparative methods.
对高分子的研究不仅仅是化学的一个分支；它是化学科学的一个新维度。
"Mathematics is the science of patterns, and we study them to learn how to think logically, critically, and creatively."
The past is a kind of future that has already happened.