已知函数y=ax2+bx+c的图象过点A(0,-5),B(5,0),它的对称轴为直线x=2,则这个二次函数的解析式为( )。
y=x2-4x-5
我国规定,各级各类规划之间要保证衔接,有关政府部门应在收到规划草案之日起( )个工作日内反馈衔接意见。
A.10
B.20
C.30
D.60
Your brother has washed all the clothes by himself, _______?[ ]
A. is he
B. does he
C. doesn’t he
D. hasn’t he