Serezha looked attentively at his teacher, at his thin little beard and his spectacles which had slipped down the bridge of his nose, and became so engrossed in thought that he no longer heard what his teacher was explaining.
Sergio miró atentamente al profesor, examinó su barba rala, sus lentes que descendían más abajo de la señal que le hacían sobre la nariz, y quedó tan hundido en sus reflexiones que no entendió ya nada de lo que le explicaba.