从亚当和夏娃时代到农业发明之前，人类的生存一定是岌岌可危的，因为他无法确保自己的食物供应。
性别平等的未竟事业是我们这个时代的决定性挑战之一。
释义：在富贵时，朋友无数；一旦遭遇困难，却无人帮助。
The great secret that all old people share is that you really haven't changed in seventy or eighty years. Your body changes, but you don't change at all.
The study of mathematics is like air or water to the development of science.
The truth is often found in contradiction.
