为什么score代表20？各位英语高手帮忙解答一下！

"Score" 是与“share”有关, 来源于古挪威语“skor”意为符木或者割符，即在一根木棒上刻数字或字符号，用于计数。通常人们数20为一个单位，每数到第20个的符木就会比其他的大些，所以“score”也就表示20。另外，dozen是代表12，不是13。

〔单复同〕二十;（指称猪、牛等用的重量单位）二十（或二十一）磅
a (three) score of people
二十（六十）人

score (n.)late Old English scoru "twenty," from Old Norse skor "mark, tally," also, in Icelandic, "twenty," from Proto-Germanic *skura-, from PIE root *(s)ker- "to cut" (cf. Old English sceran; see shear).

The connecting notion is perhaps counting large numbers (of sheep, etc.)
with a notch in a stick for each 20. This counting notion is the origin
of the modern sense in sports (1742, originally in whist). In Old
French, "twenty" (vint) or a multiple of it could be used as a base, e.g. vint et doze ("32"), dous vinz et diz
("50"). Meaning "printed piece of music" first recorded 1701, from the
practice of connecting related staves by scores of lines.

score 得分 的意思
a dozen 英语里 ”一打“ 就是十三个

为什么一打是12，谁能给我解释😄