PENICILLIN（青霉素）

If you leave a piece of bread in a warm damp place, mould will soon grow

on it . when this happens, we say the bread"has gone mouldy". mould can grow on all kinds of things besides food. It grows from spores which are in the air.

If the conditions are right, a spore can

quickly get around and form amould. this happens quite commonly. we have all probably seen it.

In

1928, Sir Alexander Fleming found that mould had killed some germs he was trying to grow in his lab.

If he had not noticedthis, the world would have lost one of the greatest discoveries of the century. Fleming called the substance

"penicillin".

Because penicillin can kill germs，

doctors use it to treat diseases. It has saved millions of lives. Scientists grow large quantities of common mould so

that they can get penicillin from it in

order to make antibiotics , that is, substances that kill germs. Next time

you see some mould on a piece of

bread, remember that it is one of man's

greatest friends!

penicillin青霉素 damp潮湿的 mould霉

mouldy发霉的 spore孢子 commomly普通，通常 Sir Alexander Fleming亚历山大.弗来明爵士 germ细菌 substance物质

treat治疗 disease疾病 quantity数量

antibiotics抗生素

译文：如果你把一块面包放在一个潮湿温暖的地方，它上面会很快长出霉来。这时候，我们说面包“发霉了”。霉会在包括食物在内的各种各样的东西上长出来。它来源于空气中的孢子。如果环境适宜，一个孢子会很快变成团并形成霉。这种现象很普通，我们能看见这个过程。

1928年，亚历山大.弗来明爵士发现在实验室里培育的霉杀死了一些细菌。如果他没注意到这些，一个世纪前世界将错过一项最伟大的发明。弗来明爵士給这种物质命名“青霉素”。

因为青霉素能杀死细菌，医生用它来治疗疾病。它挽救了数以万计的生命。科学家大量培育普通的霉，从中得到青霉素来制取抗生素，也就是说，能杀死细菌的物质。以后你在一块面包上看见霉了，记住它是人类的一个好朋友！