Leave a piece of fresh fish lying around for a few days in the warmth of summer and try to forget about it. You can’t! Within a day or so it starts to decay and gives off the indescribable smell only rotten fish can give off. Pick pears from a tree and forget to eat them and soon your pears will be ‘sleepy’, or over-ripe and mushy, and useless for any purpose. These are just two common examples of food spoilage that may occur.
Fortunately today there are a great many ways of preserving foods that enable us to enjoy all kinds of meats, fruits, and vegetables out of season and from other countries.
Just how and why do foods spoil? Why does fish go rotten, butter turn rancid, milk sour, and pears “sleepy”? Basically there are two means by which food spoilage occurs. One is by the growth of micro-organisms on the outside, and the other is by chemical changes on the inside. Micro-organisms such as yeasts, molds, and bacteria are always present in the air around us. They settle on food and, if the conditions are right, begin to break it down. Some yeasts tend to make food ferment. They change sugar into alcohol, which then turns into acid making the food taste sour. Molds tend to grow on moist foods. You have probably seen the greenish-colored mold on bread and on cheese. It starts as tiny white spores and grows into a greenish mass, on the surface at first and then gradually right through. The food develops a musty taste.
The sour and musty foods are not necessarily harmful. But some kinds of bacterial spoilage can be dangerous. Certain bacteria produce toxins which cause food poisoning. The worst thing about them is that they may be present even where there are no outward signs of decay. Botulism is the most deadly form of food poisoning of this kind. It is almost always fatal. But the toxins are destroyed by cooking, as are most toxins. Chemical spoilage may occur as a result of several processes. Contact with the air oxidizes foods such as butter which contain fats and oils, and makes them rancid. Substances called enzymes, which are present in all living things, are responsible for food spoilage, too. Their action, if limited, is beneficial. For example, they act on meat and make it more tender.
All methods of food preservation aim to prevent the growth of any micro-organisms, and prevent or arrest the action of other agents causing decay. Canning, bottling and freezing are the most common methods of food preservation today. Drying and curing are methods that have been practiced for centuries in one form or another, and they are still very important. Two up-to-date methods use radiation and antibiotics (especially for poultry) to sterilize and preserve foodstuffs, but they are not used on anywhere near the same scale as the other methods. Pasteurization is another method of temporary preservation used for milk.
1. The word “sleepy” in line 4 of paragraph 1 most probably means ______.
2. From paragraph 3, we can infer that ______.
3. According to the author, some sour and musty foods are ______.
4. The best title for this passage would be ______.
5. The word “they” in line 3 of paragraph 4 refers to ______.
6. Enzymes are ______.
7. All of the following are mentioned as ways of food preservation methods EXCEPT ______.
问题1选项
A.tired and ready for sleep
B.inactive or slow-moving
C.beginning to spoil
D.beginning to sleep
问题2选项
A.foods spoils because of chemical changes in the outside
B.foods go rotten by two means
C.fish spoils faster than pears
D.microorganisms outside foods are responsible for spoilage of foods
问题3选项
A.beneficial to human body
B.caused by molds and ferments
C.poisons
D.as tasty as the fresh ones
问题4选项
A.Why Fish Spoil
B.Bacteria Are Not Always Harmful
C.Pasteurization Can Prevent Food Spoilage
D.Food Preservation
问题5选项
A.certain bacteria
B.toxins
C.outward signs
D.some kinds of bacterial of spoilage
问题6选项
A.harmful to human beings
B.beneficial to all living things
C.useless to human beings
D.found in all living things
问题7选项
A.canning and bottling
B.freezing and drying
C.using radiation and antibiotics
D.pasteurization and cooking
第1题:C
第2题:D
第3题:B
第4题:D
第5题:B
第6题:D
第7题:D
第1题:
【选项释义】
The word “sleepy” in line 4 of paragraph 1 most probably means ______. 第一段第四行中的单词“sleepy”很可能是______的意思。
A. tired and ready for sleep A. 累了，准备睡觉了
B. inactive or slow-moving B. 不活跃的或者行动缓慢的
C. beginning to spoil C. 开始变质
D. beginning to sleep D. 开始睡觉
【考查点】词汇推断题
【解题思路】根据原文：Pick pears from a tree and forget to eat them and soon your pears will be…, or over-ripe and mushy, and useless for any purpose.（从树上摘的梨，忘了吃，很快它就会……，或者过熟和变糊，变得毫无用处。）可推知“sleepy”指的是梨子变坏，故选项C正确。
【干扰项排除】A、B、D选项根据解析可知，属于曲解原文。
第2题:
【选项释义】
From paragraph 3, we can infer that ______. 从第3段，我们可以推断出______。
A. foods spoils because of chemical changes in the outside A. 食物变质是因为外面发生了化学变化
B. foods go rotten by two means B. 食物腐烂有两种途径
C. fish spoils faster than pears C. 鱼比梨坏得快
D. microorganisms outside foods are responsible for spoilage of foods D. 食物外的微生物是导致食物变质的原因
【考查点】推理判断题
【解题思路】文中提到：One is by the growth of micro-organisms on the outside, and the other is by chemical changes on the inside.（一种是外部微生物的生长，另一种是内部的化学变化。）可推知D选项与原文相符，所以正确。
【干扰项排除】
A选项根据解析可知属于曲解原文；
B选项是原文事实细节内容：Basically there are two means by which food spoilage occurs.（基本上有两种方式发生食物腐败。），不用推理出来，不符题意；
C选项在文中没有提及，属于无中生有。
第3题:
【选项释义】
According to the author, some sour and musty foods are ______. 根据作者的说法，一些酸的和发霉的食物是______。
A. beneficial to human body A. 对人体有益
B. caused by molds and ferments B. 由霉菌和酶引起的
C. poisons C. 毒药
D. as tasty as the fresh ones D. 和新鲜的一样好吃
【考查点】事实细节题
【解题思路】根据第三段；They change sugar into alcohol, which then turns into acid making the food taste sour. Molds tend to grow on moist foods.（酵母把糖变成酒精，酒精又变成酸，从而导致食物变酸。霉菌容易在潮湿的食物上生长。）可知选项B正确。
【干扰项排除】
A、D选项在文中没有提及，属于无中生有；
C选项，第四段第一句提到：The sour and musty foods are not necessarily harmful. But some kinds of bacterial spoilage can be dangerous. Certain bacteria produce toxins which cause food poisoning.（酸的发霉的食物不一定有害。但有些种类的细菌腐败可能是危险的。某些细菌会产生毒素，导致食物中毒。）可知酸的和发霉的食物不是毒药，而是一些被特定细菌污染的食物，属于张冠李戴。
第4题:
【选项释义】
The best title for this passage would be ______. 这篇文章最好的标题是______。
A. Why Fish Spoil A. 鱼为什么会腐坏
B. Bacteria Are Not Always Harmful B. 细菌并不总是有害的
C. Pasteurization Can Prevent Food Spoilage C. 巴氏杀菌可以防止食物腐败
D. Food Preservation D. 食物保藏
【考查点】主旨大意题
【解题思路】结合全文内容，本文首先提出食物变质的例子，第二段提到了现在有很多的保存食物的方法，然后通过分析食物变质的原因，最后提出关于食物保存的方法，所以选项D最能概括全文主旨。
【干扰项排除】A、B、C选项过于片面，不能用于总结全文。
第5题:
【选项释义】
The word “they” in line 3 of paragraph 4 refers to ______. 第四段第三行中的“他们”一词指的是______。
A. certain bacteria A. 特定的细菌
B. toxins B. 毒素
C. outward signs C. 外在迹象
D. some kinds of bacterial of spoilage D. 一些变质的细菌
【考查点】推理判断题
【解题思路】根据该词所在的原文句意：某些细菌会产生毒素，导致食物中毒。最糟糕的是，即使在没有明显腐烂迹象的地方，它们也可能存在。由此可知，“they”指代的是细菌产生的毒素，所以选项B正确。
【干扰项排除】A、C、D选项不能通过文章信息推理出来。
第6题:
【选项释义】
Enzymes are ______. 酶是________。
A. harmful to human beings A. 对人类有害的
B. beneficial to all living things B. 对所有生物有益
C. useless to human beings C. 对人类无用
D. found in all living things D. 所有生物中都有
【考查点】事实细节题
【解题思路】文中倒数第二段的倒数第二句提到：Substances called enzymes, which are present in all living things, are responsible for food spoilage, too.可知，选项D与原文表述一致。
【干扰项排除】
A、C选项根据常识可知是错误的，且根据文章内容：The sour and musty foods are not necessarily harmful.（酸味和霉味食品不一定有害。）和Their action, if limited, is beneficial. For example, they act on meat and make it more tender.（它们的作用，如果是有限的，是有益的。例如，它们作用于肉类，使其更加嫩。）可知酶是有帮助的且不一定对人体有害；
B选项过于绝对，属于过度推断。
第7题:
【选项释义】
All of the following are mentioned as ways of food preservation methods EXCEPT ______. 下面所有食物保存方法除了______都提到了。
A. canning and bottling A. 罐装和装瓶
B. freezing and drying B. 冷冻和干燥
C. using radiation and antibiotics C. 使用辐射和抗生素
D. pasteurization and cooking D. 巴氏杀菌和烹饪
【考查点】事实细节题
【解题思路】cooking在文中没有提及，故选D。
【干扰项排除】
A、B、C选项根据文章内容：Canning, bottling and freezing are the most common methods of food preservation today. Drying and curing are methods that have been practiced for centuries in one form or another, and they are still very important. Two up-to-date methods use radiation and antibiotics (especially for poultry) to sterilize and preserve foodstuffs, but they are not used on anywhere near the same scale as the other methods.（罐头、装瓶和冷冻是当今最常见的食品保存方法。干燥和腌制是几个世纪以来一直以这种或那种形式实行的方法，它们仍然非常重要。有两种最新的方法使用辐射和抗生素（特别是对家禽）来消毒和保存食品，但它们的使用规模远不及其他方法。）可知在文中都提到了，故不符合题意。
