The greatest obstacle to being heroic is the doubt whether one may not be going to prove one's self a fool; the truest heroism is to resist the doubt; and the profoundest wisdom, to know when it ought to be resisted, and when it be obeyed.
水产养殖成功的真正标准不仅是产量，还有栖息地的保护。
我是一个正在进行中的作品。
Illustrations should not just decorate the text; they should expand it.
In science, there is no such thing as a final answer.