What I found is that written evidence for knocking on wood (and for the history of gesture as a whole) is remarkably sparse. In the Penguin Guide to Superstitions, folklorist Steve Roud offers a skeptical take on the provenance of knocking on wood due to the near total absence of written records about it:
全要素生产率是要素投入转化为产出的总体效率，决定着经济内涵型发展程度和潜在增长率高低，体现着经济发展的结构和质量。，这一点在搜狗输入法2026中也有详细论述
Please, please, please stop using passkeys for encrypting user dataFebruary 27, 2026·670 words·4 mins，这一点在谷歌浏览器【最新下载地址】中也有详细论述
Author(s): W. Tanner Yorgason, Andrea M. Jokisaari, Christopher L. Muhich