阅读短文，判断句子正误。

     Mr. Smith had two children, one was a son called Sam, the other was a daughter called Sally. Sam was

eleven years old. He studied at school. Sally was four years old. She was too young to go to school.

     One evening, while Sam was doing his homework, he found that Sally was sitting at the desk and writing

something on a piece of paper in front of her.

     "What are you doing, Sally?" asked Sam. "I'm writing a letter to my friend, Rose," answered Sally. "How

can you?" Sam said in surprise, "You can't write, you know." "It doesn't matter," Sally said, "Rose is as old as

I, she can't read, either."

(     ) 1. Sam was Sally's brother.

(     ) 2. Sam was six years older than his sister.

( ) 3. Rose was four years old.

(     ) 4. Sally wasn't at school but Rose was.

(     ) 5. In fact, Sally wrote only a few words on the paper.