温度骤降，水银柱迅速跌落。

The temperature suddenly dropped, causing the mercury to ___plunge rapidly.

他猛地将钥匙插进了锁孔。

He ___plunged the key into the keyhole forcefully.

她一听到这个消息就立刻投身于慈善工作中。

She ___plunged into charity work as soon as she heard the news.

股市暴跌导致投资者损失惨重。

The stock market ___plunged, causing huge losses for investors.

游泳运动员从跳台上迅速跳入水中。

The swimmer ___plunged into the water from the diving board.