【问】 像hope，beauty，disease，liberty，success这样一些抽象名词本是不可数名词，为什么
 有时候也能遇到它们的复数形式呢?
 【答】 当抽象名词用作它的本义时，属不可数名词范畴，是没有复数形式的。例如：
 1. She never completely gave up hope…
 她从不完全放弃希望……
 2. She learned to appreciate beauty. (EED)
 她学习欣赏美的东西。
 3. Disease is usually caused by germs. (ALD)
 疾病一般是细菌引起的。
 4. He has had great success in his life. (ALD)
 他在一生中做出很大的成就。
 但是，当抽象名词转而表达具体的事物，若干种类或具体的结果时，就变成可数名词而可以有复数形式了。
 1. Parents have high hopes for their children.(各种希望或强烈的希望)
 父母都望子成龙。
 2. She had turned into a beauty. (EED)
 她出落成一个美人。
 3. With him，I explored all the beauties of pre-war Warsaw.(各种各样的美丽之处)
 我同他一起考查了战前华沙所有的美丽景点。
 4. Measles，mumps and influenza are common diseases. (ALD)
 麻疹、流行性腮腺炎和流感是常见的疾病。
 5. There are a number of pronounced successes to his credit，but he has not as yet attainedto full success. (Curme)
 他取得许多显著成绩，但他还没有获得完全成功。
 6. No，it wasn’t their manners that bewildered me，but their manner.
 不，并不是他们的礼貌，而是他们的态度使我迷惑不解。
 7. Science demands that theories must be tested by careful experiment and calculation.
 (Chambers)
 科学要求理论必须经过仔细的实验和计算的检验。
 8. Biology，chemistry，and astronomy are natural sciences. (Thorndike)
 生物学、化学和天文学是自然科学。
 (参见success/a success，science/sciences)