阅读下面短文，把A～E五个句子填入文中的空缺处，使短文内容完整正确。

A small boy wanted to ask for two days off, but he had only learnt the expression “have a dayoff”．　　1　　 He came to the teacher’s office and said, “Mother is ill．May I have a day off, sir?” “Of course, you can, ” answered the teacher at once．　　2　　 As soon as he was out of the room, he turned back and knocked at the teacher’s door again．“May I have a day off again?” he asked．　　3　　 “Didn’t you say it just now?” “Yes, sir．　　4　　” “Why didn’t you say‘ May I have two days off’?” the teacher said with a smile．“ 　　5　　 ”the boy answered．

A．But you didn’t teach me to say so．

B．The teacher was very surprised．

C．He thought hard, and he had an idea．

D．The boy walked away．

E．But I can’t be here the day after tomorrow, either．