This is the 17336th most frequent Korean word.
선별한
"Selected" or "screened."
In this instance, '선별한' qualifies '책들', signifying that these books were picked out with purpose or criteria applied.
도서관에서 선별한 책들은 유익합니다.
The selected books from the library are beneficial.
Here, '선별한' describes '과일', indicating that the fruits offered for sale have been sorted or chosen specifically.
우리는 선별한 과일만 판매합니다.
We only sell selected fruits.
In this sentence, '선별한' is used as an adjective modifying '자료', meaning the materials have been selected or chosen carefully.