Which sentence is a supporting detail that you should get enough sleep?

Which sentence is a supporting detail that recycling is important?

Matilda Excerpt

By Roald Dahl

By the time she was three, Matilda had taught herself to read by studying newspapers and magazines that lay around the house. At the age of four, she could read fast and well and she naturally began hankering after books. The only book in the whole of this enlightened household was something called Easy Cooking belonging to her mother, and when she had read this from cover to cover and had learnt all the recipes by heart, she decided she wanted something more interesting. "Daddy," she said, "do you think you could buy me a book?" "A book,” he said. "Whatd' you want a flaming book for?" "To read, Daddy." "What's wrong with the telly, for heaven's sake? We've got a lovely telly with a twelve-inch screen and now you come asking for a book! You're getting spoiled, my girl!"

What is the main idea?