Miss Read is good ____________ music. She is good ____________ children in the music club.
A:at; at
B:with; with
C:at; with
D:with; at
正方体是特殊的长方体。
下列属于复杂反射(条件反射)的是( )
在极坐标系中,点 2,2π3 到圆ρ=2cosθ 的圆心的距离为( )