词汇与表达：plunge-dive-diving

plunge
If something or someone plunges in a particular direction, especially into water, they fall, rush, or throw themselves in that direction.
At least 50 people died when a bus plunged into a river...
一辆公共汽车栽进河里，造成至少50人丧生。
The stock market took a plunge yesterday.
股票市场在昨天突然暴跌。

dive
If you dive into some water, you jump in head-first with your arms held straight above your head.
He tried to escape by diving into a river...
他企图跳入河中逃跑。