เพราะเพื่อนทุกคนในห้องเงียบตั้งใจเรียนและฟังที่ครูสอน
Because a friend to everyone in the room knows that classroom teachers and is intended to.
Because everyone in the room was silent and listen attentively to the teacher.
Because a friend of everyone in the room, quiet study hard and listen to the teacher.