They learn that if you just stare at a student and raise your eyebrow about a quarter of an inch, you don't have to say a word because they know that that means that you want more.
ただ生徒をじっと見つめ 眉を数ミリ動かすだけで 言葉がなくとも 彼らはそれが“もっと欲しい”と 意味することを分かるようになります