A. No.It's on the first floor.
B Thank you.
C. Yes,it is.
D. It's next to my classroom.
— Tom wants to know if you will have a picnic tomorrow.— Yes, but if it_______, we'll play chess instead.
如图,抛物线经过A(﹣1,0),B(5,0),C(0,- 52 )三点.