Bacteria are extremely small living things. While we measure our own sizes in inches or centimeters, bacterial1 size is measured in microns. One micron is a thousandth of a millimeter: a pinhead is about a millimeter across. Rod-shaped bacteria are usually from two to four microns long, while rounded ones are generally one micron in diameter. Thus if you enlarged a rounded bacterium2 a thousand times, it would be just about the size of a pinhead. An adult human magnified by the same amount would be over a mile(1.6 kilometer) tall.
Even with an ordinary microscope, you must look closely to see bacteria. Using a magnification of 100 times, one finds that bacteria are barely visible as tiny rods or dots. One cannot make out anything of their structure. Using special stains, one can see that some bacteria have attached to them wavy-looking “hairs” called flagella3. Others have only one flagellum. The flagella rotate, pushing the bacteria through the water. Many bacteria lack flagella and cannot move about by their own power, while others can glide4 along over surfaces by some little-understood mechanism5.
From the bacteria point of view, the world is a very different place from what it is to humans. To a bacterium water is as thick as molasses is to us. Bacteria are so small that they are influenced by the movements of the chemical molecules6 around them. Bacteria under the microscope, even those with no flagella, often bounce about in the water. This is because they collide with the watery7 molecules and are pushed this way and that. Molecules move so rapidly that within a tenth of a second the molecules around a bacteria have all been replaced by new ones; even bacteria without flagella are thus constantly exposed to a changing environment.
細(xì)菌細(xì)菌是極其微小的生物體。我們用英寸或厘米來(lái)測(cè)量自己的大小，而測(cè)量細(xì)菌卻要用微米。一微米等于千分之一毫米。針頭直徑大約一毫米。
棒狀細(xì)菌通常有2～4微米長(zhǎng)，而圓形細(xì)菌的直徑一般只有1微米。因此，即使你把一個(gè)圓形細(xì)菌放大1000倍，它也不過(guò)一個(gè)針頭那么大。
可是如果把一個(gè)成年人放大1000倍，就會(huì)變成1英里(或1.6公里)多高。用一般的顯微鏡觀察細(xì)菌時(shí)，你必須仔細(xì)觀察才能看見(jiàn)它們。使用
100倍的顯微鏡時(shí)，你會(huì)發(fā)現(xiàn)細(xì)菌不過(guò)是隱約可見(jiàn)的小細(xì)棒或小點(diǎn)點(diǎn)，而它們的結(jié)構(gòu)你卻根本看不出來(lái)。使
用特殊的著色劑后，你會(huì)發(fā)現(xiàn)有的細(xì)菌上長(zhǎng)著不少波狀的"毛發(fā)"即鞭毛，而有的細(xì)菌只有一根鞭毛。鞭毛的旋轉(zhuǎn)可以推動(dòng)細(xì)菌在水中行進(jìn)。
不少細(xì)菌沒(méi)有鞭毛，因而不能自己行進(jìn)。還有些細(xì)菌卻能通過(guò)某些鮮為人知的機(jī)制沿物體表面滑動(dòng)。我們所熟知的世界在細(xì)菌眼中完全是另一個(gè)樣子。
對(duì)于細(xì)菌來(lái)說(shuō)，水就同糖漿之于人類一樣稠密。細(xì)菌是如此的微小，周圍化學(xué)分子的一舉一動(dòng)都會(huì)對(duì)它們產(chǎn)生影響。在顯微鏡下，細(xì)菌，甚至包括那些沒(méi)有鞭
毛的細(xì)菌，經(jīng)常在水中跳來(lái)跳去。這是因?yàn)樗鼈兣c水分子相撞后，被彈向各個(gè)方向。分子移動(dòng)很迅速，僅0.1
秒之隔，一個(gè)細(xì)菌周圍的分子就會(huì)完全更新。因此，即使是沒(méi)有鞭毛的細(xì)菌也暴露在一個(gè)不斷變化的環(huán)境中
1 bacterial
a.細(xì)菌的
參考例句：
Bacterial reproduction is accelerated in weightless space. 在失重的空間，細(xì)菌繁殖加快了。
Brain lesions can be caused by bacterial infections. 大腦損傷可能由細(xì)菌感染引起。
2 bacterium
n.(pl.)bacteria 細(xì)菌
參考例句：
The bacterium possibly goes in the human body by the mouth.細(xì)菌可能通過(guò)口進(jìn)入人體。
A bacterium is identified as the cause for his duodenal ulcer.一種細(xì)菌被斷定為造成他十二指腸潰瘍的根源。
3 flagella
n.鞭節(jié)，鞭毛
參考例句：
The rotation of flagella pushes the bacteria through the water.鞭毛的旋轉(zhuǎn)可以推動(dòng)細(xì)菌在水中行進(jìn)。
Many protoctistans are motile,using pseudopodia,cilia or flagella.許多原生動(dòng)物利用偽足、纖毛或鞭毛能運(yùn)動(dòng)。
4 glide
n./v.溜，滑行；(時(shí)間)消逝
參考例句：
We stood in silence watching the snake glide effortlessly.我們噤若寒蟬地站著，眼看那條蛇逍遙自在地游來(lái)游去。
So graceful was the ballerina that she just seemed to glide.那芭蕾舞女演員翩躚起舞，宛如滑翔。
5 mechanism
n.機(jī)械裝置；機(jī)構(gòu)，結(jié)構(gòu)
參考例句：
The bones and muscles are parts of the mechanism of the body.骨骼和肌肉是人體的組成部件。
The mechanism of the machine is very complicated.這臺(tái)機(jī)器的結(jié)構(gòu)是非常復(fù)雜的。
6 molecules
分子( molecule的名詞復(fù)數(shù) )
參考例句：
The structure of molecules can be seen under an electron microscope. 分子的結(jié)構(gòu)可在電子顯微鏡下觀察到。
Inside the reactor the large molecules are cracked into smaller molecules. 在反應(yīng)堆里，大分子裂變?yōu)樾》肿印?BR> 7 watery
adj.有水的，水汪汪的；濕的，濕潤(rùn)的
參考例句：
In his watery eyes there is an expression of distrust.他那含淚的眼睛流露出驚惶失措的神情。
Her eyes became watery because of the smoke.因?yàn)闊熝?，她的雙眼變得淚汪汪的。
Even with an ordinary microscope, you must look closely to see bacteria. Using a magnification of 100 times, one finds that bacteria are barely visible as tiny rods or dots. One cannot make out anything of their structure. Using special stains, one can see that some bacteria have attached to them wavy-looking “hairs” called flagella3. Others have only one flagellum. The flagella rotate, pushing the bacteria through the water. Many bacteria lack flagella and cannot move about by their own power, while others can glide4 along over surfaces by some little-understood mechanism5.
From the bacteria point of view, the world is a very different place from what it is to humans. To a bacterium water is as thick as molasses is to us. Bacteria are so small that they are influenced by the movements of the chemical molecules6 around them. Bacteria under the microscope, even those with no flagella, often bounce about in the water. This is because they collide with the watery7 molecules and are pushed this way and that. Molecules move so rapidly that within a tenth of a second the molecules around a bacteria have all been replaced by new ones; even bacteria without flagella are thus constantly exposed to a changing environment.
細(xì)菌細(xì)菌是極其微小的生物體。我們用英寸或厘米來(lái)測(cè)量自己的大小，而測(cè)量細(xì)菌卻要用微米。一微米等于千分之一毫米。針頭直徑大約一毫米。
棒狀細(xì)菌通常有2～4微米長(zhǎng)，而圓形細(xì)菌的直徑一般只有1微米。因此，即使你把一個(gè)圓形細(xì)菌放大1000倍，它也不過(guò)一個(gè)針頭那么大。
可是如果把一個(gè)成年人放大1000倍，就會(huì)變成1英里(或1.6公里)多高。用一般的顯微鏡觀察細(xì)菌時(shí)，你必須仔細(xì)觀察才能看見(jiàn)它們。使用
100倍的顯微鏡時(shí)，你會(huì)發(fā)現(xiàn)細(xì)菌不過(guò)是隱約可見(jiàn)的小細(xì)棒或小點(diǎn)點(diǎn)，而它們的結(jié)構(gòu)你卻根本看不出來(lái)。使
用特殊的著色劑后，你會(huì)發(fā)現(xiàn)有的細(xì)菌上長(zhǎng)著不少波狀的"毛發(fā)"即鞭毛，而有的細(xì)菌只有一根鞭毛。鞭毛的旋轉(zhuǎn)可以推動(dòng)細(xì)菌在水中行進(jìn)。
不少細(xì)菌沒(méi)有鞭毛，因而不能自己行進(jìn)。還有些細(xì)菌卻能通過(guò)某些鮮為人知的機(jī)制沿物體表面滑動(dòng)。我們所熟知的世界在細(xì)菌眼中完全是另一個(gè)樣子。
對(duì)于細(xì)菌來(lái)說(shuō)，水就同糖漿之于人類一樣稠密。細(xì)菌是如此的微小，周圍化學(xué)分子的一舉一動(dòng)都會(huì)對(duì)它們產(chǎn)生影響。在顯微鏡下，細(xì)菌，甚至包括那些沒(méi)有鞭
毛的細(xì)菌，經(jīng)常在水中跳來(lái)跳去。這是因?yàn)樗鼈兣c水分子相撞后，被彈向各個(gè)方向。分子移動(dòng)很迅速，僅0.1
秒之隔，一個(gè)細(xì)菌周圍的分子就會(huì)完全更新。因此，即使是沒(méi)有鞭毛的細(xì)菌也暴露在一個(gè)不斷變化的環(huán)境中
1 bacterial
a.細(xì)菌的
參考例句：
Bacterial reproduction is accelerated in weightless space. 在失重的空間，細(xì)菌繁殖加快了。
Brain lesions can be caused by bacterial infections. 大腦損傷可能由細(xì)菌感染引起。
2 bacterium
n.(pl.)bacteria 細(xì)菌
參考例句：
The bacterium possibly goes in the human body by the mouth.細(xì)菌可能通過(guò)口進(jìn)入人體。
A bacterium is identified as the cause for his duodenal ulcer.一種細(xì)菌被斷定為造成他十二指腸潰瘍的根源。
3 flagella
n.鞭節(jié)，鞭毛
參考例句：
The rotation of flagella pushes the bacteria through the water.鞭毛的旋轉(zhuǎn)可以推動(dòng)細(xì)菌在水中行進(jìn)。
Many protoctistans are motile,using pseudopodia,cilia or flagella.許多原生動(dòng)物利用偽足、纖毛或鞭毛能運(yùn)動(dòng)。
4 glide
n./v.溜，滑行；(時(shí)間)消逝
參考例句：
We stood in silence watching the snake glide effortlessly.我們噤若寒蟬地站著，眼看那條蛇逍遙自在地游來(lái)游去。
So graceful was the ballerina that she just seemed to glide.那芭蕾舞女演員翩躚起舞，宛如滑翔。
5 mechanism
n.機(jī)械裝置；機(jī)構(gòu)，結(jié)構(gòu)
參考例句：
The bones and muscles are parts of the mechanism of the body.骨骼和肌肉是人體的組成部件。
The mechanism of the machine is very complicated.這臺(tái)機(jī)器的結(jié)構(gòu)是非常復(fù)雜的。
6 molecules
分子( molecule的名詞復(fù)數(shù) )
參考例句：
The structure of molecules can be seen under an electron microscope. 分子的結(jié)構(gòu)可在電子顯微鏡下觀察到。
Inside the reactor the large molecules are cracked into smaller molecules. 在反應(yīng)堆里，大分子裂變?yōu)樾》肿印?BR> 7 watery
adj.有水的，水汪汪的；濕的，濕潤(rùn)的
參考例句：
In his watery eyes there is an expression of distrust.他那含淚的眼睛流露出驚惶失措的神情。
Her eyes became watery because of the smoke.因?yàn)闊熝?，她的雙眼變得淚汪汪的。