Alcohol may be a medical disinfectant, but should not be relied upon to sterilize water.

alcohol ^{n. 1. [U] the colorless liquid that is found in drinks such as beer, wine, etc. and is used in medicines, cleaning products, etc. = ethanol 酒精，乙醇}

• Wine usually contains about 10% alcohol.
• levels of alcohol in the blood
• Choose an alcohol-free skin toner if you have dry skin.

alcohol ^{n. 2. [U] drinks containing this 含酒精的饮料，酒prohibit the sale of alcohol.}

• I never touch alcohol.
• For many young people drinking alcohol is a sign of 'growing up'. 

sterilize ^{v. 1. to make sth. completely clean by killing any bacteria in it  消毒}

• Sterilize the bottles with boiling water.
• Boiling is an effective way to sterilize water for drinking.^{煮沸是一种给饮用水消毒的有效方式。}
• The equipment is designed to sterilize water using UV light.^{该设备设计成使用紫外线给水消毒。}

sterilize ^{v. 2. if a person or animal is sterilized, they have an operation to stop them producing babies 使绝育}

• My wife was sterilized after the birth of her fourth child.
• We do not sterilize land in perpetuity. ^{对土地没有永久性损害。}
• Cockroach sterilization agent can sterilize cockroach and can be new insecticide against cockroach. ^{蟑螂绝育剂能够使蟑螂绝育，可以作为一种新型灭蟑药物。}

Ethanol is more effective at a concentration of 50-70 per cent; below 20 per cent, its bactericidal action is negligible.

小常识：95% 或者 100% 的酒精一碰到细菌，会瞬间凝固细菌表面蛋白，像给其裹上一层坚硬的保护壳，酒精进不去内里，则杀不死细菌，而75%左右的浓度，杀菌效果最好。

concentration ^{n. [C] the amount of a substance contained in a liquid 浓度}

• allowable concentrations of pesticides in drinking water
• High concentrations of toxic elements were found in the polluted areas of the sea.
• No studies found that eating breakfast was bad for concentration. ^{没有研究发现吃早餐不利于注意力的集中。}
• The cleaning agent is most effective at a concentration of 1:10 with water.^{这种清洁剂在与水以 1:10 的浓度下最有效。}

bactericidal action ^{杀菌作用；杀菌效果}

• The drug's bactericidal action rapidly eliminated the infection.^{这种药物的杀菌作用迅速消除了感染。}
• The drug has different degrees of effects on 11 species of bacteria tested in the bacteriostasis and bactericidal action.^{该药物对受试的11种病原菌都有不同程度的杀菌、抑菌作用。}
• The higher the surface voltage, the greater the effect of bacteriostasis or bactericidal action of electret on staphylococci aureus. ^{驻极体的表面电位越高，对金黄色葡萄球菌的抑菌效果越好。}

action ^{n. the effect that a substance, esp. a chemical, has on sth. 作用，效果，影响}

• the action of alcohol on the liver
• the action of certain chemicals on the brain

be negligible ^{adj. of very little importance or size and not worth considering = insignificant 微不足道的}

• The cost was negligible.
• The risk of contamination is negligible with proper handling.^{在正确操作下，污染的风险可以忽略不计。}
• The price difference between the two models is negligible.^{这两个型号之间的价格差异可以忽略不计。}

Spirits labelled 95 proof contain only about 47 per cent alcohol.

spirit ^{n. [C usually plural] a strong alcoholic drink such as whisky or brandy 烈性酒}

• I don't drink spirits.
• Whisky, brandy and rum are all spirits.

label ^{v. to attach a label onto sth. or write information on sth. 给（某事物） 加标签或标记}

• The file was labelled ‘Top Secret’.
• You should check the expiry date on goods labelled 'fresh'.^{你应该检查标记为“新鲜”的商品的保质期。}
• The product is one of the many items labelled 'organic' in the supermarket.^{该产品是超市里许多标记为“有机”的物品之一。}

proof ^{n. a measurement of the strength of some types of alcoholic drink, esp. spirits 酒的度数}

• _(Br.E.) 70% proof vodka ( = that contains 70% pure alcohol)   
• _(Am.E.) 70 proof vodka ( = that contains 35% pure alcohol)

contain only about... ^{仅含有大约…}

• The sample was surprisingly pure and contained only about a trace of impurities.^{这个样品出奇地纯净，仅含有大约微量的杂质。}
• The small bottle of medication contains only about ten doses.^{这小瓶药仅含有大约十剂。}

Beware of methylated alcohol, which is very poisonous, and should never be added to drinking water.

beware ^{adj. (used only in the infinitive and imperative 仅用于不定式及祈使句) used to warn someone to be careful because sth. is dangerous 当心，提防}

• Motorists have been warned to beware of icy roads.
• Beware of saying anything that might reveal where you live.
• Travellers should beware of pickpockets in crowded tourist areas.^{旅行者应提防拥挤旅游区的小偷。}
• Please beware of the wet floor after the cleaning staff have finished.^{清洁人员完成后，请提防湿滑的地面。}