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 fundamental point in fabricating a chain reacting machine is of course to see to it that each fission produces a certain number of neutrons and some of these neutrons will again produce fission.
记忆不仅是个人的事情，也是集体的事情。
森林不仅仅是一种资源；它是我们留给后代的遗产。
You are the author of your own life.
You are never too old to set another goal or to dream a new dream.
我们都是时代的产物，无论好坏。