Question

какой корень в слове первоклассница

Answer 1

Перв - корень о - суффикс класс - корень
Ниц - суффикс а - окончание

Answer 2

Тут 2 корня ... перв (о - суффикс) класс ... ниц - суффикс , а - окончание . 

Answer 3

Root of the Word "Первоклассница"

The word "первоклассница" consists of two parts: "перво-" and "-классница". The root of the word is "класс" which means "class" in English.

Root of the word "первоклассница": "класс"

This information is supported by the search snippet from Source which mentions the word "класс" in the context of educational terms.

Now, you have a better understanding of the root of the word "первоклассница"! If you have any more questions or need further clarification, feel free to ask.