原文视听

Her destination is Mexico
它的目的地是墨西哥
and one small and special group of trees.
和一小群独特的树木
No-one knows how she finds them, in these great mountain forests.
在这大片的山林里 谁也不知道它是怎么找到的
She joins other monarch butterflies
它和其他帝王斑蝶作伴
that have travelled here from all over North America.
一路飞越北美到这儿来
Countless butterflies crowd these particular trees,
数之不尽的蝴蝶 聚集在这些树上
hanging from every branch.
悬挂在每根枝娅上
They come here because, although winter brings a chill to the air,
它们飞到这儿来 是因为尽管冬天的空气变得冷冽
there will not be a lethal freeze as there will in Canada.
还不至于像加拿大那样 把它们冻死
The conditions are perfect for hibernation.
这里的环境最适合冬眠
Hibernating butterflies are vulnerable to predators.
冬眠的蝴蝶 是掠食动物眼中的肥羊
But monarchs are poisonous.
但帝王斑蝶带有毒性
However, a few birds have learned to rip out the toxic parts and eat the rest.
不过有些鸟儿 学会扯掉有毒的部分
They kill hundreds of thousands of butterflies
把剩下的吃进肚里 几千只蝴蝶死在它们手里
and dislodge many more.
被赶走的更多
Those that fall must get back into the trees before nightfall brings another killer.
落下的蝴蝶必须回到树上 否则夜里又出现另一个杀手
They vibrate their wings to warm their flight muscles.
它们振动翅膀为飞行肌肉加温
But it's a race against time.
但这是一场和时间的赛跑
Night brings a lethal ground frost.
夜晚带来致命的地面霜

重点解释

The conditions are perfect for hibernation.这里的环境最适合冬眠

perfect for对 ... 来说最理想的

This snow's perfect for a snowball fight.

这雪打雪仗极好。

The weather is perfect for a garden party.

这是举行露天聚会的理想天气。

However, a few birds have learned to rip out the toxic parts and eat the rest.不过有些鸟学会扯掉有毒的部分

a few一些(用于可数名词之前）

A few jokes will add a final fillip to your speech.

几句笑话会给你的演说添些生气。

John vamped up a few rumors to discredit his enemy.

约翰编造一些谣言去中伤他的敌人。

rip out扯掉

She ripped out the torn pockets of the coat.

她撕下了上衣的破袋。

learn to学习

I must learn to snatch at every chance to meet him.

我必须学会抓住一切机会同他见面。

She learn to triumph over her disability.

她学会了战胜她自身的不足。