教室（きょうしつ）に入（はい）って席に着（せきにつ）くのとほぼ同時（どうじ）に、始業（しぎょう）を知（し）らせるチャイムの音（おと）が鳴り響（なりひび）く。

About the same time as he entered the classroom and arrived at his seat, the chime to announce class rings across the school.