热心网友
in one's teens
热心网友
When he/she was a teen-ager.When he/she was teen-age.When he/she was a teen-aged boy/girl.
热心网友
at one's tens
热心网友
He/She is early tens.
热心网友
对，来晚了
热心网友
1)At teen-age2)When he/she was in teenage
热心网友
When he/she was a teen-ager.When he/she was teen-age.When he/she was a teen-aged boy/girl.