根据短文内容判断下列句子正误。

                                                                                                                 B

    One day, a little boy met an old millionaire and said. “I think I'm much richer than you.” The old man was greatly surprised and asked, “Why, my child?"

    “Do you know, time is money?” The boy asked.

    “Of course I do, but does it mean you are richer than me?”

     "Why not?" said the boy, “Now you see, I'm only ten years old and you are already seventy. If we both can live to 100, I still have 90 years to 90, while you have only 30 years. Time is money. Don't you agree I'm much richer than you?”

计算：$2\cos 45°-{\left(\pi +1\right)}^0+\sqrt{\frac{1}{4}}+{\left(\frac{1}{2}\right)}^{-1}$；