把二次函数y=x²﹣12x化为形如y=a（x﹣h）²+k的形式____ 

阅读下列短文，从下面每小题的A、B、C、D四个选项中选出最佳选项。

    What should you do if you don't have a lot of time, but still want to get healthier?

    Don't worry. You're not alone. Most people want to get healthier and look younger, but they can't seem to have the time for it.

     Here are four ways for you to be healthy:

1. ______________

      If you haven't got time for anything else in the morning, make time to drink a big glass of water. We lose a lot of energy through the night, so we need to replenish (补充) it with water. Drink a glass of water and in a week you'll begin to feel less tired.

2. Get some fresh fruit on your way out.

    Wherever you're going -- whether it's a walk or a drive to the supermarket or on your way to a meeting --- pick up some fruit and eat it. Fruit is rich in nutrients (营养素) and sugar that our bodies need.

3 To do exercise is very important.

    If you work in an office, get up every 30 minutes and go for a walk, If you have an office with stairs, run up and down the stairs every couple of hours.

4. Deep breathing.

    When you've got time -- at your desk or taking a break -- do some deep breathing. It is good for your health too.