時差N小時:眼鏡蛇噴射毒液時如何百發(fā)百中?

Don:Hey Yael, why are you wearing safety goggles?

唐：嘿，雅艾爾，你為什么戴著一副護目鏡?

Yael:In case I run into any spitting cobras, Don.

雅艾爾：唐，以防碰上吐毒液的眼鏡蛇。

Don:Spitting cobras? I didn't know there were anywild cobras in the United States.

唐：吐毒液的眼鏡蛇?我一直以為在美國沒有野生的眼鏡蛇。

Yael:There aren't. Cobras live in Africa and Asiawhere they kill thousands of people each year, butI'm going to the reptile exhibit at the zoo. The scarything is, some cobra species don't even have to bite you to injure you. They can spit poison adistance of three feet and they always aim for the eyes. Their poison is a neurotoxin thatcauses pain and can damage the mucus membranes and cornea. It can even cause blindness.

雅艾爾：這里沒有。眼鏡蛇生活在非洲和亞洲，每年有上千人死于這種蛇。但我要去動物園的爬行動物館參觀?？膳碌氖?，有些種類的眼鏡蛇不用咬你就可以傷到你。它們能在三尺以內(nèi)吐出毒液，目標(biāo)往往是眼睛。它們的毒液是一種神經(jīng)毒素，能導(dǎo)致疼痛并使粘液隔膜和角膜毀壞。甚至能導(dǎo)致失明。

Don:Wow.

唐：哇。

Yael:And that's not all. Scientists have found that they can hit a target about two feet awaywith one-hundred-percent accuracy.

雅艾爾：那還不是全部?？茖W(xué)家們還發(fā)現(xiàn)，它們能在兩尺遠的地方百分之百地擊中目標(biāo)。

Don:I don't think I could spit that well.

唐：我想我都不能吐唾液到那么遠。

Yael:The snakes don't really spit. The poison is released from openings in the front of theirfangs. As it's released, they expel air from their lungs to blow the poison outward.Researchers used high-speed photography to find out how they hit their target every time.Instead of holding their head still to spit, the snakes rotate it from side to side, spreading thepoison over an area.

雅艾爾：蛇不會真的噴射唾液。毒液是從毒牙前部的張口處分泌出來的。毒液釋放時，肺部迅速排出空氣，將毒液注射到外界。研究人員用高速攝像機捕捉到它們每次是如何命中目標(biāo)的。與其保持頭部靜止，蛇會一邊旋轉(zhuǎn)頭部，一邊將毒液散播出去。

Don:So, it's like using a shot gun with lots of pellets instead of a rifle with a single bullet.

唐：那么，這就像使用一桿有很多子彈的散彈槍，而不是只有一發(fā)子彈的步槍。

Yael:Exactly. The snakes don't need to aim perfectly, they just need to be close.

雅艾爾：正是。蛇并不需要瞄準(zhǔn)的多么精確，離得夠近就行了。

Don:That is interesting, Yael. But aren't the zoo snakes in glass enclosures?

唐：雅艾爾，那很有趣。但是動物園里的蛇不是被玻璃墻擋著嗎?

Yael:I imagine so. But better safe than sorry.

雅艾爾：我想是的。但是安全起見，以免后悔。