Pregnancy is Insane · Kurzgesagt – In a Nutshell
揭秘怀孕过程中精子与卵子的激烈竞争，了解生命诞生背后的生物学奇迹。适合练习英语听力和阅读理解。
Pregnancy is a hardcore sci-fi epic of war, peace and compromise.
怀孕这部作品堪称一部充满战争、和平与妥协元素的硬核科幻史诗。
Babies are basically very cute tumors that grow a completely new organ inside a different human.
婴儿其实就像是一些非常可爱的“肿瘤”：它们在另一个人的体内逐渐发育出一个全新的器官。
Their mom’s body graciously allows this, while the new life saps her resources and challenges her immune system to its limits for months.
他们母亲的身体“欣然”允许这一切发生；与此同时，新生命的诞生耗尽了她的体力资源，并在数月时间里对她免疫系统造成了极大的压力（使其功能接近极限）。
Biology is brutal and beautiful and metal.
生物学既残酷又美丽，同时还充满着“金属般的坚硬质感”（即其规律性与逻辑性的严密性）。
Let us zoom in and observe this brutal struggle for survival – that in the best case ends in one of the most magical things:
让我们放大画面，仔细观察这场残酷的生存斗争吧。在最好的情况下，这场斗争最终会带来最神奇的结果之一……
A new life.
新的生活。
Our story begins with an army of tens of millions of sperm cells that immediately face death.
我们的故事始于数以亿计的精子细胞——它们一诞生就面临着死亡的命运。
They are on a tight timer before they run out of energy and die.
他们在有限的时间内必须行动；否则能量耗尽后就会死亡。
But this is the least of their problems right now.
但这对他们来说，目前只是最不重要的问题罢了。
Like all bodily openings, the female reproductive tract is a fortress defending against invaders.
与身体的所有开口部位一样，女性的生殖道也是一道防御外来入侵者的“堡垒”。
The future mom’s body has set up
这位准妈妈的体内已经开始了相应的生理变化（即身体正在为怀孕做准备）。
deadly barriers and puts the sperm through a brutal process that kills almost all of them and ideally selects the strongest and fittest one.
这些“致命的屏障”会对精子进行一系列严酷的筛选过程：几乎所有的精子都会在此过程中被杀死，只有最强壮、最适应环境的精子才能存活下来。
The first deadly obstacle is a highly acidic environment guarded by hundreds of thousands of guard cells.
第一个致命的障碍是一个酸性极强的环境，该环境由数十万个保卫细胞（即专门用于抵御外来入侵的细胞）所守护。
The acidity kills millions, especially of the weaker sperm within the first half hour, although they have a bit of protection:
这种酸性环境会在半小时内杀死数百万精子（尤其是那些较为脆弱的精子）；不过，精子本身也具备一定的保护机制。
Seminal fluid is alkaline and so it makes this first obstacle a little less deadly.
精液呈碱性，因此这一初始障碍的“致命性”（即对精子造成的伤害）会降低一些。
The survivors reach the next obstacle, a treacherous maze full of protein nets where millions more find a brutal end getting stuck and lost.
幸存者们来到了下一个障碍——一个充满危险陷阱的迷宫。这个迷宫里布满了由蛋白质制成的网状结构；数以百万计的生物在这里被困住、迷失方向，最终惨遭死亡。
Now if a woman is in the part of her menstrual cycle where she is ovulating , her body helps the sperm out a bit,
如果女性正处于月经周期中的排卵期，她的身体会帮助精子更顺利地通过生殖道。
by releasing chemicals that guide the way and by being a bit less hostile.
通过释放能够引导方向的化学物质，以及降低自身的“敌对性”（即减少对其他生物的攻击性），来实现这一目标。
Luckily for our brave sperm this is the case today.
幸运的是，对于我们这些“勇敢的精子”来说，如今情况确实如此。
Only a couple hundred – less than 0.0001% of the original sperm – pass through into the uterine cavity,
只有几百个精子能够成功通过输卵管，进入子宫腔；这些精子仅占原始精子总数的不到0.0001%。
where two tunnels branch out.
两条隧道在这里分岔。
Here mucus helps transport the stronger sperm to move on, while weeding out the weaker ones.
在这里，黏液的作用是帮助那些更健康的精子继续前进，同时将那些较弱的精子淘汰掉。
The mom’s immune cells pick off and devour every cell that trails behind or takes the wrong turn.
这位母亲的免疫细胞会识别并摧毁所有那些掉队或走错方向的细胞。
And then finally, maybe just a few dozen sperm reach their goal, the mighty, giant egg.
最后，也许只有几十个精子能够成功抵达它们的目标——那个庞大而神秘的卵子。
10,000 times bigger than them, it is an industrial scale monster loaded with nutrients and nearly 100,000 mitochondria,
它的体积比那些生物大一万倍，堪称一个“工业级”的庞然大物——体内富含各种营养物质，同时拥有近十万个线粒体。
the powerhouse of the cell – 50 times more than an average cell.
细胞的“动力源”：其能量输出是普通细胞的50倍。
But the egg is not easily conquered
不过，这个“难题”并不容易解决（或者说：这个“障碍”并不容易被克服）。
– the survivors get closer and try to get in until the egg decides to accept a single one of them.
幸存者们逐渐靠近，试图进入那个“蛋”内部；直到那个“蛋”最终决定接纳其中一个人为止。
The genes of two individuals merge.
两个个体的基因发生了融合。
The egg stops being part of its mother – it is something else now.
这个卵不再属于它的“母亲”了；它现在已经变成了另一种存在。
A new being with its own agenda.
一个拥有自己目标的新生命体。
Not a human yet, but the potential to become one.
虽然目前还不是一个真正的人类，但却具备成为人类的潜力。
Like a thought that is not yet a word.
就像一个尚未转化为语言的念头……
But its mom’s body hasn’t decided yet if she wants to say it out loud.
但是它的妈妈还没有决定是否要大声说出来。
It will have to fight for that.
为此，它必须付出努力（或进行斗争）。
For a few days it rapidly divides and grows to a couple of hundred cells, while traveling down to the uterus,
在最初的几天里，这些细胞会迅速分裂并增长到几百个；同时，它们会沿着输卵管向子宫方向移动。
the part of the female reproductive system where it will try to make its new home.
女性生殖系统中那个会试图成为新生命“栖息地”的部分。
Here it begins to divide into two specialised teams of cells - one will eventually become the baby.
从这里开始，这些细胞会分裂成两个专门化的细胞群；其中一个最终会发育成婴儿。
The other cells are trophoblasts and their job is to turn into a temporary organ inside the mother:
其他细胞属于滋养层细胞（trophoblasts），它们的作用是在母体内发育成一个临时性的器官。
the placenta, that will make pregnancy possible and eventually die.
胎盘：它使妊娠成为可能，但最终会死亡。