单项选择题 下列含磷有机化合物中具有对映异构体的是：

单项选择题 雅可比矩阵内部各项不直接含有速度值，但是雅可比矩阵影响速度 A、正确 B、错误

单项选择题 Why do Chinese people paste a reversed character Fu on the door or the wall when Spring Festival comes? A、Because they think it is interesting to do so. B、Because they want to be different from others. C、Because it signifies the arrival of blessings. D、Because it looks more beautiful.