asian mothers engaged in twice as many social routines, teaching politeness norms like greetings.

teaching 부분이요..
관계대명사 which it taught에서 which와is이 생략된 관계대명사 문장인지..
아님,
and they(asian mothers) taught 에서 접속사and와 주어 they가 생략되어 분사구문 문장인지.

asian mothers engaged in twice as many social routines, teaching politeness norms like greetings.
- asian mothers engaged in twice as many social routines, (whichis)teaching politeness norms like greetings.
- asian mothers engaged in twice as many social routines,and they taughtpoliteness norms like greetings.

무엇이 맞는건가요?

제가 보기엔 분사구문으로 보는게 더 맞는것 같습니다..
선생님들 생각은 어떠신가요?^^