An Essential Correction

Teacher: Walter, why don't you wash your face? I can see what you had for breakfast this morning.
Walter: 　What was it?
Teacher: Eggs.
Walter: 　Wrong. That was yesterday.

老　师：沃尔特，你为什么不洗脸?我看得出你今天早饭吃了什么。
沃尔特：我吃了什么？
老　师：鸡蛋。
沃尔特：错了，老师。那是昨天吃的。