瞬间秒杀听力 第485期:死亡暗流（在线收听）

It is a pity that every summer

a few people drown at the beach.

In some cases,

these people were good swimmers.

So how did it happen? Riptide!

Riptide is a strong underwater current.

It moves quickly away

from shore and out to sea.

It appears suddenly and pulls its victim

under and far off shore.

Therefore, people should make it a rule

never to swim too far out from the beach.

很遗憾，每年夏天总有一些人在海边溺水身亡，

而这些溺水的人中有些是很会游泳的。

那么这究竟是怎么发生的呢?

是激流在作祟！

激流是海面下一种强大的暗流，

从海岸迅速地流向大海。

它出现的时候毫无预警，

会将受害者拉下水面并拖离岸边。

因此，人们应该养成

不要游得离海滩边太远的习惯。