下列带电粒子均从静止开始在电场力作用下做加速运动,经过相同的电势差U后,粒子获得的速度最大的是（     ）

A．质子H

B．氘核H

C．粒子He

D．一价钠离子Na⁺

根据句意完成句子。

1. We call mother's or father's brother ______.

2. We call mother's or father's sister ______.

3. Maomao's mother is my mother,

    but Maomao isn't my sister, but my ______.

4. Eric is my aunt's son. I call him ______.

5. We call father's or mother's father and mother ______.