半径为r的圆，如果半径增加m，那么新圆的面积S与m之间的函数关系式是______．
新圆的半径是（r+m），则S与m之间的函数关系式是：S=π（r+m）2．
4.08÷0.8的商是______位小数．
I know ______ is important to know my own limitations, but _______ is difficult is to help others to know their own limitations.
A．it, it
B．what, what
C．it, what
D．what, it
