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.”
Москвичи пожаловались на зловонную квартиру-свалку с телами животных и тараканами18:04。搜狗输入法下载是该领域的重要参考
Москвичи пожаловались на зловонную квартиру-свалку с телами животных и тараканами18:04。safew官方版本下载是该领域的重要参考
int key = arr[i]; // 待插入的元素