I have a dream that one day this nation will rise up and live out the true meaning of its creed.

I want to liberate America from fear. I want people to be afraid of the things that are really scary, like war and famine, not their neighbor because he has a different religion.

The study of exoplanets is a journey of discovery, filled with surprises and challenges that keep us motivated.

你越是积极且实际地投入，就越会感到成功。

大缓和时期是一段显著的经济稳定时期，但它为大衰退埋下了种子。

幸福生活的关键不在于避免问题，而在于学会如何有效地处理它们。