如图所示，质量为m，带电量为q的粒子，以初速度v₀，从A点竖直向上射入空气中的沿水平方向的匀强电场中，粒子通过电场中B点时，速率v_B=2v₀，方向与电场的方向一致，则A，B两点的电势差为（   ）

读句子，选择合适的答句。

(____) 1. Where is the art room?

(____) 2. Is it on the second floor?

(____) 3. How many students?

(____) 4. Is this your computer room?

(____) 5. Do you have an art room?

A. It's on the first floor.

B. Forty-five students.

C. No, it isn't.

D. Yes, it is my computer coom.

E. Yes, we do.