B1 中級 美國腔 1127 分類 收藏
開始影片後,點擊或框選字幕可以立即查詢單字
字庫載入中…
回報字幕錯誤
This is the deadliest animal in the world.
Mosquitoes kill hundreds of thousands of people each year, the most vulnerable people: children, pregnant women…
No other bite kills more humans—or makes more of us sick.
[Anopheles gambiae, Malaria] [Andes aegypti, Zika, dengue fever, chikungunya] [Culex pipiens, West Nile Virus disease]
So what makes a mosquito's bite so effective?
For starters, they're motivated.
Only females bite us—hey need blood to make eggs.
And a pool of water for their babies to hatch in.
Even a piece of trash can hold enough.
At first glance, it looks simple: this mosquito digging her proboscis into us.
But the tools she's using here are sophisticated.
First, a protective sheath retracts—see it bending back?
If you look at a mosquito's head under a microscope, you can see what that sheath protects.
And inside there are six needles.
Two of them have tiny teeth.
She uses those to saw through the skin.
They're so sharp you can barely feel her pushing.
These other two needles hold the tissues apart while she works.
From under the skin, you can see her probing, looking for a blood vessel.
Receptors on the tip of one of her other needles pick up on chemicals that our blood vessels exude naturally and guide her to it.
Then she uses this same needle like a straw.
As her gut fills up, she separates water from the blood and squeezes it out.
See that drop?
That frees up space to stuff herself with more nutritious red blood cells.
With another needle, she spits chemicals into us.
They get our blood flowing more easily, and give us itchy welts afterwards.
And sometimes, before she pries herself away, she leaves a parting gift in her saliva.
A virus or a parasite that can sicken or kill us.
There's nothing in it for her.
The viruses and parasites are just hitching a ride.
But this is what makes mortal enemies out of us and mosquitoes.
They take our blood.
Sometimes we take theirs, but often, not soon enough.
Good—you're still there!
These are the larvae of Culex pipiens, a.k.a. the common house mosquito here in California.
Gross, right? Well, you can avoid them by emptying your rain gutters.
Pet water dishes too.
While you're at it, subscribe!
We have so many more science videos coming your way. See you next time!
提示:點選文章或是影片下面的字幕單字,可以直接快速翻譯喔!

載入中…

載入中…

蚊子不要來!可怕的蚊子其實有六根針?! (How Mosquitoes Use Six Needles to Suck Your Blood | Deep Look)

1127 分類 收藏
Mackenzie 發佈於 2020 年 2 月 19 日    Mackenzie 翻譯    adam 審核
看更多推薦影片
  1. 1. 單字查詢

    在字幕上選取單字即可即時查詢單字喔!

  2. 2. 單句重複播放

    可重複聽取一句單句,加強聽力!

  3. 3. 使用快速鍵

    使用影片快速鍵,讓學習更有效率!

  4. 4. 關閉語言字幕

    進階版練習可關閉字幕純聽英文哦!

  5. 5. 內嵌播放器

    可以將英文字幕學習播放器內嵌到部落格等地方喔

  6. 6. 展開播放器

    可隱藏右方全文及字典欄位,觀看影片更舒適!

  1. 英文聽力測驗

    挑戰字幕英文聽力測驗!

  1. 點擊展開筆記本讓你看的更舒服

  1. UrbanDictionary 俚語字典整合查詢。一般字典查詢不到你滿意的解譯,不妨使用「俚語字典」,或許會讓你有滿意的答案喔