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classroom; lecture room
department (in a university)
class; lessons; course
school (for a particular discipline); teaching establishment
教室に誰もいなかったよ。
Nobody was in the classroom.
教室は建物の三階にあります。
The classroom is on the third floor of the building.
新しい教室はとても広くて窓も大きかった。
The new classroom was very spacious with large windows.