题目

阅读理解Dear John, My name is Amber and I want to share my story with you because what you've shared about life and positive energy has changed my life. This past year has been one of the hardest for me. I felt I was stuck in a position that had nothing to do with what I wanted to do with my life. In January, after two years of being together, my boyfriend left me. I read your blog every morning as I drink my coffee at work, but it wasn't until this March that I told myself no more negativity as you taught readers in your blog. Since then I've got into new habits at work to keep my energy （2008•黄石）先化简后求值：，其中a=-1+，b=-1-．