一皮球停在水平地面上，在某时开始向东做直线运动，经过5m与墙相碰．碰后向西做直线运动，经过7m停下，则上述过程中皮球通过的路程和位移分别是（规定向东方向为正方向）（　　）

根据短文理解完成下列各题。

Do you like South Korean actor Lee Min Ho? The "flower boy" plays a cool secret agent(特工) in his new TV drama City Hunter (《城市猎人》). To play the part well, Lee did many unusual things like riding an elephant and standing on top of a big tree.

About Lee Min Ho Birthday: June 22, 1987 Height: 186cm Weight: 69kg Favourite food: meat

Favourite colors: black, white and red

若z= $\frac{1}{2}$ + $\frac{\sqrt{3}}{2}$ i，且（x﹣z）⁴=a₀x⁴+a₁x³+a₂x²+a₃x+a₄，则a₂等于（    ）