Progress requires both vision and execution.

Handy measure: the distance between your fingertips of your outstretched arms at shoulder level is your height.

现代世界的巨大挑战是创建既足够强大以有效治理，又对公民需求负责和响应的制度。

物理学的魅力在于它能够用简单的原理解释复杂的事物。