1) Old friends are not to be neglected.

故旧不弃。
2) Not to throw away an old friend

故知不弃
3) Old friends are not to be neglected

故旧不遗
5) Change new for the old

弃旧换新
补充资料:故旧
旧友(总称):亲戚~。
说明:补充资料仅用于学习参考,请勿用于其它任何用途。
参考词条