The key to success is to keep learning and adapting.

至今一切社会的历史都是阶级斗争的历史，即剥削阶级和被剥削阶级之间、统治阶级和被压迫阶级之间斗争的历史。

世界是一本书，不旅行的人只读了一页。

The reason that the invisible hand often seems invisible is that it is often not there.

The structure of DNA was a puzzle that demanded to be solved.

People, even more than things, have to be restored, revived, reclaimed and redeemed;never throw out anyone.