Talk 3 与细菌共舞
Wors Tips
bacteria n.细菌 nutrient n.营养物，滋养物
critter n.生物 generic adj.一般的，通用的
trillion n.万亿，兆 metric n.度量标准
armor n.装甲，盔甲 immune adj.免疫的
microbe n.细菌，微生物
Listen to the following recording and answer questions 1-3.
1）A.They are uni-cell microscopic organisms.
B.They only have a single piece of DNA.
C.They can survive independent of the environment.
D.They reproduce by dividing themselves into two sections.
2）A.about a trillion B.10 trillion C.30，000 D.10 billion
3）A.They absorb the nutrients from human body.
B.They facilitate the operation of immune system.
C.They help human beings cope with outside pressure.
D.They make people sick via environmental insults.
听力原文
Bacteria are the oldest living organisms on the earth.They’ve been here for billions of years，and what they are single-celled microscopic organisms.So they are one cell and they have this special property that they only have one piece of DNA.They have very few genes，and genetic information to encode all of the traits that they carry out.And the way bacteria make a living is that they consume nutrients from the environment，they grow to twice their size，they cut themselves down in the middle，and one cell becomes two，and so on and so on.They just grow and divide，and grow and divide—so a kind of boring life，except that what I would argue is that you have an amazing interaction with these critters.
I know you guys think of yourself as humans，and this is sort of how I think of you.This man is supposed to represent a generic human being，and all of the circles in that man are all of the cells that make up your body.There is about a trillion human cells that make each one of us who we are and able to do all the things that we do，but you have 10 trillion bacterial cells in you or on you at any moment in your life.So，10 times more bacterial cells than human cells on a human being.And of course it’s the DNA that counts，so here’s all the A，T，Gs and Cs that make up your genetic code，and give you all your charming characteristics.You have about 30，000 genes.Well it turns out you have 100 times more bacterial genes playing a role in you or on you all of your life.At the best，you’re 10 percent human，but more likely about one percent human，depending on which of these metrics you like.I know you think of yourself as human beings，but I think of you as 90 or 99 percent bacteria.
These bacteria are not passive riders，these are incredibly important，they keep us alive.They cover us in an invisible body armor that keeps environmental insults out so that we stay healthy.They digest our food；they make our vitamins；they actually educate your immune system to keep bad microbes out.So they do all these amazing things that help us and are vital for keeping us alive，and they never get any press for that.But they get a lot of press because they do a lot of terrible things as well.So，there’s all kinds of bacteria on the Earth that have no business being in you or on you at any time，and if they are，they make you incredibly sick.
Questions：
1.According to the speech，which of the following is NOT true about bacteria？
2.How many bacteria cells are there in or on a person at any moment in his or her life？
3.What is the function of bacteria to the health of human being？
参考译文
细菌是地球上最古老的生物。它们已经存在数十亿年了。它们是单细胞微生物。它们的特征是只有一个细胞，还有就是它们只有一份DNA。它们只有少量基因和遗传信息来编码它们携带的特性。细菌生存的方法是不断从环境中吸取养分。在成长到两倍的体积后，它们从中一分为二，分裂为两个细胞，如此循环。它们不停地生长、分裂，然后再生长、再分裂——过着有点乏味的生活。但是，今天我想告诉你，你与这些细菌有着惊人的互动关系。
我知道你认为你自己是人类，而我可能也是这样看你们的。在这里的是一个普通人类的代表，在他身上所有的圆圈代表着各个组成人体的细胞。每个人体大约是由一兆个人体细胞所组成，它们让我们能完成各种各样我们想做的事情。但是，你一生中的每时每刻，有大约十兆个细菌细胞生活在你的体内体表。所以，有十倍于人体细胞的细菌细胞生活在一个人身上。当然，DNA也很重要。所有的A，T，G和C（腺嘌呤，胸腺嘧啶，鸟嘌呤，胞嘧啶）组成你的基因密码，赋予你所有的魅力特征。你有3万左右的遗传基因，而在你的一生中，在你体内体表始终扮演着重要角色的细菌的遗传基因数量是你自己基因数量的100倍。最乐观的看法是：你只是“十分之一人”，事实上“百分之一人”更准确，取决于你更喜欢用哪个尺度来衡量。我知道你自认为是一个“人类”，但在我眼里你是90%～99%的细菌。
这些细菌不是顺从的乘客，他们难以置信的重要，他们让我们活着。它们是我们身上的无形盔甲，阻断来自环境的伤害以确保我们的健康。它们帮我们消化食物、制造维生素，它们还指导你的免疫系统，将有害微生物阻挡在体外。它们尽心尽职干活，帮助我们，维护我们的生命，却从没有因此得到过报道。反而却因为它们同时做的许多坏事而时常见报。地球上有无数种细菌，它们有些在任何时候都绝对不应该出现在你的体内体表，然而假如你不幸遇到了，那你一定会病得很厉害。
参考答案
1.C 2.B 3.B