单项选择题已知边际成入为,其收入函数为。正确错误
单项选择题. A、11V、-5.5V B、10V、-5.5V C、10V、5.5V D、11V、5.5V
单项选择题A、正确 B、错误
单项选择题There are difficult people everywhere. But ________that sometimes the difficult person is YOU rather than the other party you regard as difficult.
单项选择题(2Z,4E)-2,4-庚二烯的结构是下列哪一个