The reason ____ I have to go is _____ my mother is ill in hospital.

A．why ; why

B．why; because

C．why ; that

D．that; because

载脂蛋白生理功能的叙述，错误的是

A．稳定脂蛋白结构
B．转运游离脂肪酸
C．识别脂蛋白受体
D．调节脂蛋白代谢有关酶的活性
E．促进脂质在脂蛋白间交换