阅读短文，回答问题。
In an English class, Miss Green checks homework. She asks Mike, "What is your favourite fruit, Mike?"
"Strawberries." Mike answers.
"Well, please spell the word, strawberry." says Miss Green.
"Oh, I change my mind. My favourite fruit is an apple." Mike says.
1. What kind of fruit does Mike like best?
2. What does Miss Green ask him to do?
3. Why does he change his mind?
