It is better to keep your mouth closed and let people think you are a fool than to open it and remove all doubt.

闭嘴不言让别人怀疑你是个傻子,比张嘴说话让人完全不再怀疑,要好的多。

马克·吐温(Mark Twain),1835年-1910年,美国作家、演说家,著有《百万英镑》等。