new-broom (2)youdaoicibaDictYouDict[new-broom 词源字典]
"To set about making widespread or fundamental changes. Also with object: to make (one's way) like a new broom", 1950s; earliest use found in Ngaio Marsh (1895–1982), detective novelist and theatre director. From new broom.[new-broom etymology, new-broom origin, 英语词源]