Living in Australia? Try the Guardian Australia’s daily sports newsletter
他先刮胡子。拿着那面上世纪八九十年代的塑料镜，对着下巴一遍遍推。泡沫刮干净后，又用毛巾擦脸，顺手把原本就锃亮的光头再擦了一遍。
The “Knocking on Wood” Wikipedia page mentions Roud’s conclusion, and this claim of a 19th century origin has circulated online as the final say on the matter. If you go back to the original, though, Roud’s proposal actually ends on an ambivalent note: “Before this theory [of 19th century origins] can be finally accepted, however, an examination of the history of European forms of this custom would be advisable.”
Chad Whitacre Head of Open Source, Sentry