下列运算正确的是( )
A:a2•a3=a6
B:7a2﹣a2=7
C:﹣(-12)-2•(xy2)3=﹣4x3y6
D:(2m﹣n)2=4m2+n2
— When are you going to fly to Taiwan this summer?— _________ we finish school. It will be a great holiday.