题目

In the famous fairy tale, Snow White eats the Queen’s apple and falls victim to a curse; in Shakespeare’s novel, Romeo drinks the poison and dies; some ancient Chinese emperors took pills that contained mercury, believing that it would make them live for ever, but they died afterward.    Poison has long been an important ingredient in literature and history, and it seems to always be connected with evil, danger and death. But how much do you really know about poison?    An exhibition, The Power of Poison, opened last month at the American Museum of Natural History in New York,若点是角终边上异于原点的一点,则的值为(    ) A、           B、             C、           D、