What will the students do in the classroom first?
The teacher witnessed him putting a cigarette in his mouth in the classroom.
The teacher had only been gone for five minutes, but the university students had completely trashed the classroom.
The teaching room is just a classroom.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.