—— _________ does your cousin go to the gym?                                                                                   

——Twice a week.                                                                                                      

若非零实数m，n满足m（m﹣4n）=0，则分式$\frac{m^2+1}{m^2-2mn}-\frac{1}{2mn}$的值为（　　）

下列有关哺乳动物与人类关系的叙述中错误的是（　　）