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.”
黎智英欺詐案上訴得直：定罪及刑罰被撤銷，出獄時間提前
。WPS官方版本下载对此有专业解读
JOIN issues i ON i.repo_id = c.repo_id。关于这个话题，91视频提供了深入分析
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