if one knows the past,one can infer the future ❍ ～，所以要重视历史经验。It is imperative to pay attention to historical lessons,for if one knows the past,one can infer the future.
数往知来shǔ wǎnɡ zhī lái
往：过去；来：未来。了解了过去，就可以推测到未来。In retracing the past, the future can be known.