基数，用符号表示，代表一系列中这样的单元中的第一个。

The cardinal number, represented by the symbol, designating the first such unit in a series.

youdao

基数，用符号表示，代表一系列中这样的单元中的第一个。

The cardinal number, represented by the symbol, designating the first such unit in a series.

youdao