This is the 10226th most frequent Korean word.
광역전철에서
"On the metropolitan subway."
In this sentence, '광역전철에서' emphasizes the location where the action of reading books is intended to take place, which is on the metropolitan railroad.
광역전철에서 읽을 책을 가지고 다녀야 해요.
You should carry books to read on the metropolitan railroad.
Here, '광역전철에서' introduces the subject of the sentence and specifies that the described action occurs on the metropolitan railroad.
광역전철에서 사람들이 많이 탑승합니다.
Many people board on the metropolitan railroad.
In this sentence, '광역전철에서' sets the context for the action of getting off, specifying the location as the metropolitan railroad.