题目

You may wonder whether stress (焦虑) is a serious matter. The answer is “Yes”. You should realize that stress is a risk to your health. If you want to live a long and healthy life, you need to begin to guard against stress from a young age.Here are some ways to deal with stress and bring balance (平衡) to your life:● Be positiveOne way to cancel out (消除) stress is through positive thinking. You should always look on the bright side of life, and imagine that you will have a happy and successful future.● Learn to relaxForce yourself to take a break from your studies and worries ay=f（x）的定义域为[-1，3]，则函数y=f（x2-1）的定义域为（　　）A．[-2，2]B．[-1，8]C．[0，8]D．（-2，2）