Don't____(担心) about your grandpa. Take some medicine, and he'll be better soon. Thank you, Doctor Li.
若7名学生的体重(单位:kg)分别是:40,42,43,45,47,47,58,则这组数据的平均数是( ).
— Would you like for a picnic with me?
— I'm sorry I can't.
如图,⊙M与x轴相切于原点,平行于y轴的直线交圆于P、Q两点,P在Q点的下方,若P点的坐标是(2,1),则圆心M的坐标是( )