农业实践中的微小改变可以对全球粮食安全产生重大影响。
The boundaries of our knowledge are the frontiers of our imagination.
Capitalism, then, is by nature a form or method of economic change and not only never is but never can be stationary.
古代著书立说的人,都有卓越的见解而自成一家,后世无法轻易改变。