Question

Выберите правильную форму глагола Rules became necessary when the students began/have begun to play sports.​

Answer 1

Rules became necessary when the students began to play sports.

Правило: последовательные события в прошлом выражаются Past Simple.

Answer 2

Правильная форма глагола в данном предложении - "began".

Правильное предложение: "Rules became necessary when the students began to play sports."