The number of juveniles in the general population has fallen by a fifth in the past 10 years.
在过去的10年中，青少年在总人口中所占的比重下降了1/5。
《柯林斯英汉双解大词典》
2
On the other hand, the juveniles always go against the teacher's requirement with a rebellious heart.
另一方面，青少年总是心存叛逆，违背老师的要求。
3
On the one hand, teachers impose what they believe is right on students. On the other hand, the juveniles always go against the teacher's requirement with a rebellious heart.