How did the author know that most parental-excuse notes were written by students themselves ？（）

A．The excuse notes were written in dull words.
B．The notes were more like stories than facts.
C．He called their parents and found out the truth.
D．The handwriting obviously looked like children’s.

I was in my third year of teaching writing at Ralph High School in New York, when one of my students, 15-year-old Mikey, gave me a note from his mother. It explained his absence (缺席) from class the day before:

"Dear Mr. McCort, Mikey’s grandmother, who is eighty years of age, fell down the stairs from too much coffee and I kept Mikey at home to take care of her and his baby sister so I could go to my job. Please excuse Mikey and he’ll do his best in the future. P.S. His grandmother is OK. "

I had seen Mikey writing the note at his desk. I said nothing. Most parental-excuse notes I received were penned by my students. If I were to deal with them, I’d be busy 24 hours a day. The writers of those notes didn’t realize that honest excuse notes were usually dull : "Peter was late because the alarm clock didn’t go off. "

The students always said it was bard putting 200 words together on any subject, but when they produced excuse notes, they were excellent. So I decided to type out a dozen excuse notes and gave them to my classes. I said, "They’re supposed to be written by parents, but actually they are not. True, Mikey" The students looked at me nervously.

"Now, this will be the first class to study the art of the excuse note -the first class, ever, to practice writing them. " Everyone smiled as I went on, "Today I’d like you to write An Excuse Note from Adam to God’ or ’ An Excuse Note from Eve to God’. " Heads went down. Pens raced across paper. For the first time ever I saw students so immersed (专心的) in their writing, they had to be asked to go to lunch by their friends.

The next day everyone had excuse notes. Heated discussions followed. But suddenly I saw the head at the door. He entered the classroom and walked up and down, looking at papers, and then said, "I’d like you to see me in my office. " My heart sank.

When I stepped into his office, he came to shake my hand and said, "I just want to tell you that that lesson, that task, whatever the hell you were doing, was great. Those kids were writing on the college level. Thank you. \