粒子的概念只是一种近似,仅在特定极限情况下有效。
La ironía es un arma poderosa contra la estupidez.
Collaboration across borders and industries is key to solving global food security challenges.
无铬是不够的;我们需要无愧于心。
The worst enemy of life, freedom and the common decencies is total anarchy; their second worst enemy is total power.