题目

阅读下列短文，从每题所给的四个选项（A、B、C 和 D）中，选出最佳选项。We all love chocolate, and most of usprobably eat it every day, or atleast several times a week. It is one of the most favorite kinds of food in theworld, and many would say that they can't live without it. However, there aremany facts about the world of chocolate that most people do not know. Have you everwondered where your chocolate comes from? Most of it comes from the labor ofchildren. It is said that in Africa alone, there are about 70 million childrenworking on chocolate farms. They lead a 已知双曲线的一个焦点与抛物线的焦点重合，且双曲线的实轴长是虚轴长的一半，则该双曲线的方程为          （    ） A．    B．        C．     D．