题目

通读下面短文，掌握其大意，然后在各题所给的四个选项（A、B、C和D）中选出一个最佳选项。My daughter saw a colorful rainbow the other day after a rainstorm. She asked me to look ________ the window and see it as well. Looking at it, I was amazed at how ________ beauty could make my middle­aged heart excited. As I looked at it, I also ________ the first time I ever saw a rainbow as a boy. I had been sitting in the house for an hour waiting impatiently for the rain to stop ________ I could go out and play. It had rained hard for long and I thought it would nev已知函数，则的值是（ ）A．－2 B．－1 C．0 D．1