如图所示的条形磁体旁有甲、乙、丙、丁四个能自由转动的小磁针,当小磁针静止时,其中磁极的极性标错的是( )
A:甲
B:乙
C:丙
D:丁
已知抛物线的顶点坐标为M(1,-2),且经过点N(2,3),求此二次函数的解析式.
— Excuse me, have you seen _______ umbrella here?— Yes. Is it _______ beautiful blue one? I saw it here just now.
在等比数列{an}中,a2=﹣3,a4=﹣6,则a8的值为( )
下列加线词解释有误的一项是( )