middle and high-school students
中高生向けの講座を開いた。
A course aimed at middle and high-school students was held.
中高生のスマートフォン使用が問題視されている。
The smartphone use of middle and high-school students is being viewed as a problem.
中高生が参加できる科学コンクールに多くの応募が集まった。
Many applications were received for a science contest in which middle and high-school students can take part.