learn chinese in hong kong – Bacteria

Mandarin Lesson

Bacteria

Bacteria are extremely small living things. While we measure our own sizes in inches or centimeters, bacterial 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 bacterium 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 flagella. 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 glide along over surfaces by some little-understood mechanism.

細菌

細菌是極其微小的生物體。我們用英寸或厘米來測量自己的大小,而測量細菌卻要用微米。一微米等於千分之一毫米。針頭直徑大約一毫米。棒狀細菌通常有2~4微米長,而圓形細菌的直徑一般只有1微米。因此,即使你把一個圓形細菌放大1000倍,它也不過一個針頭那麼大。可是如果把一個成年人放大1000倍,就會變成1英里(或1.6公里)多高。

用一般的顯微鏡觀察細菌時,你必須仔細觀察才能看見它們。使用100倍的顯微鏡時,你會發現細菌不過是隱約可見的小細棒或小點點,而它們的結構你卻根本看不出來。使用特殊的著色劑後,你會發現有的細菌上長著不少波狀的”毛髮”即鞭毛,而有的細菌只有一根鞭毛。鞭毛的旋轉可以推動細菌在水中行進。不少細菌沒有鞭毛,因而不能自己行進。還有些細菌卻能通過某些鮮為人知的機制沿物體表面滑動。

Xìjùn

Xìjùn shì jíqí wéixiǎo de shēngwù tǐ. Wǒmen yòng yīngcùn huò límǐ lái cèliáng zìjǐ de dàxiǎo, ér cèliáng xìjùn què yào yòng wéimǐ. Yī wéimǐ děngyú qiān fēn zhī yī háomǐ. Zhēntóu zhíjìng dàyuē yī háomǐ. Bàngzhuàng xìjùn tōngcháng yǒu 2~4 wéimǐ zhǎng, ér yuán xíng xìjùn de zhíjìng yībān zhǐyǒu 1 wéimǐ. Yīncǐ, jíshǐ nǐ bǎ yīgè yuán xíng xìjùn fàngdà 1000 bèi, tā yě bùguò yīgè zhēntóu nàme dà. Kěshì rúguǒ bǎ yīgè chéngnián rén fàngdà 1000 bèi, jiù huì biàn chéng 1 yīnglǐ (huò 1.6 Gōnglǐ) duō gāo. Yòng yībān de xiǎnwéijìng guānchá xìjùn shí, nǐ bìxū zǐxì guānchá cáinéng kànjiàn tāmen. Shǐyòng 100 bèi de xiǎnwéijìng shí, nǐ huì fāxiàn xìjùn bùguò shì yǐnyuē kějiàn de xiǎo xì bàng huò xiǎo diǎndiǎn, ér tāmen de jiégòu nǐ què gēnběn kàn bù chūlái. Shǐyòng tèshū de zhuósè jì hòu, nǐ huì fāxiàn yǒu de xìjùn shàng zhǎngzhe bù shǎo bōzhuàng de”máofǎ”jí biānmáo, ér yǒu de xìjùn zhǐyǒu yī gēn biānmáo. Biānmáo de xuánzhuǎn kěyǐ tuīdòng xìjùn zài shuǐzhōng xíngjìn. Bù shǎo xìjùn méiyǒu biānmáo, yīn’ér bùnéng zìjǐ xíngjìn. Hái yǒuxiē xìjùn què néng tōngguò mǒu xiē xiǎn wéi rénzhī de jīzhì yán wùtǐ biǎomiàn huádòng.


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