—Our class won first in the school sports meeting!
—Really? _______
A:That’s too bad!
B:I’m sorry to hear that!
C:Have fun!
D:Congratulations to you!
已知x﹣9的平方根是±3,x+y的立方根是3.
①求x,y的值;
②x﹣y的平方根是多少?