The boy wanted to ride his bike in the street, but his mother told him ________.
A:not do it
B:not to do
C:not to
D:do not to
抛物线y=2(x-3)2+1的顶点坐标为____ .
下列图示实验操作中,正确的是( )
“外甥是先皇帝舅宿亲,又蒙降金城公主,遂和同为一家。天下百姓,普皆安乐。”这段话体现了中国古代哪两个民族之前的友好关系( )