A:2
B:-2
C:1
D:-1
下列化学方程式书写正确的是( )
下列各项中,划线的成语使用不恰当的一项是( )
— Do you mind my parking here? The parking lot is full.— ______. Look at the sign! It says, “No Parking!”
边长为4cm的正方形ABCD绕它的顶点A旋转180°,顶点B所经过的路线长为____ cm.