制造链式反应机器的基本点当然是确保每次裂变产生一定数量的中子,其中一些中子将再次产生裂变。
The mind is not a passive mirror of the world but an active participant in constructing reality.
解析:学习不在数量,而在精通。
The utility of an idea determines its place in mental life.
The only thing that’s keeping me alive is the music.
The unity of Europe is a historical necessity.