原文视听

Orca - the largest and most predatory of the dolphin family.
虎鲸是最大 也最具攻击性的海豚科动物
Killer whales.
它们是杀人鲸
This pod of nine can only survive here by being opportunists.
这九只杀人鲸是因为懂得投机 才能在这里存活
Normally, young elephant seals are not on the menu.
小象海豹通常不是它们的猎物
They stay close to the shore, safe in the shallows of their nursery pool.
小象海豹都留在近岸处 安全的浅水养育池中
The pool is almost entirely cut off from the sea.
这片浅水池几乎完全与大海隔绝
A narrow, shallow channel is the only access to the open water.
只有一条狭窄浅水道通往大海
But this pod of killer whales
但这群杀人鲸当中
contains a very special female.
有一只母鲸很特殊
She's easily identified by her calf, which is always close by.
从永远紧跟在旁的幼鲸 就能轻易认出它
Every year she comes to the pool at the same time,
它每年都在同样的时间 来到这片水池
when the seals first swim in the shallows.
也就是小象海豹 最早在浅水处游动的时候
She knows how to get them.
母杀人鲸知道怎么接近它们

重点解释

They stay close to the shore, safe in the shallows of their nursery pool.小象海豹都留在近岸处，安全的浅水养育池中

close to接近于； 在 ... 的近旁

She is buying a flat close to her office.

她正在购买一套靠近她办公室的单元房。

The church is close to the school.

教堂在学校附近。

The pool is almost entirely cut off from the sea.这片浅水池几乎完全与大海隔绝

cut off使隔绝

The slide cut off the valley from the rest of the world.

山崩切断了这个山谷与外界的联系。

He was cut off from his fellows.

他和同伴失去联系。

A narrow, shallow channel is the only access to the open water.只有一条狭窄浅水道通往大海

access to接近；进入，通向…的路口

The only access to the farmhouse is across the fields.

要到那农舍去唯有穿过田地。

She was forbidden access to the club.

人家不允许她到那个俱乐部去。