我们不能忽视煤炭的经济作用，但也不能忽视其环境影响。

If not now, when? If not me, who?

"Reading is the foundation of all learning."

Vanity and pride are different things, though the words are often used synonymously.

I believe in love, but I also believe in protecting my heart.

编程是不自然的行为。

志村簇的研究是几何、代数和数论的汇合点。