覆水難收Spilled water cannot be gathered up.; Water poured on the ground cannot be recovered.; When water's spilt, you can never retrieve it.; What's done cannot be undone.; It is no use crying over spilt milk.; difficult for a divorced couple to remarry; Fallen flowers cannot go back to their stock.; Chips off the mass reverts not to the block.來者不拒refuse nobody; All are welcome.; All comers are welcome.; All's fish that comes to one's net.; keep opendoors; keep an open house; Comers are not refused admission.; grant favour to whoever asks for it; No comer is rejected.; None will be turned away.; (be) open to all; refuse nobody's request [offer]; Whoever comes will be welcome.不要混水摸魚: 渾水摸魚:fish in troubled [muddied] waters; acquire profit in time of trouble; grope for fish in turbid; profit by disturbances; profit in a confused environment; taking advantage of an accident to steal sth.