2018年12月四级真题(第三套)答案解析
全文翻译

吃掉在地上的食物真的没事吗?

A)当你把食物掉在了地上,如果你在五秒之内捡起来并吃掉,真的没事吗?一种关于食物的都市神话声 称,如果食物仅在地上停留几秒钟,灰尘和细菌还没有多少机会去污染它。(40)我们实验室的研究关注食物是 如何被污染的,且我们已就这一特别的普遍观念开展了一些工作。

B)尽管“五秒法则”看上去并不像是食品科学家们最为紧迫需要深究的问题,但是调查类似的食物传言还 是值得的,因为这形成了我们对于何时吃食物是安全的理念

C)那么地上5秒钟是否是区分可食用食物和有毒食物的关键门槛?事实比这个要更复杂。(37)这取决土 有多少细菌会在几秒内从地上到达食物上以及地面到底有多脏。

D)(43)想知道食物在掉到地上之后是否可以食用是一个很量遍的经历。同时可能也不是什么新鲜事了。 一个众所周知但并不准确的关于莱莉亚·查尔德的故事也许造成了这个食物流言。她的烹饪秀电视节目《法国 厨师》的一些观众坚持说他们看到查尔德把羊肉掉在了地上并捡起来,建议说如果他们是独自在厨房里,他们的 客人是不会知道的。

E)事实上,那是一个土豆饼,且它是掉落在灶台上,而不是地上。查尔德把它放回到平底锅里后说,“你每 次都可以把它捡起来,而且如果你是一个人在厨房,谁又会看到呢?”但是这个被记错的故事依旧流传着。更难 确定的是这个经常被引用的五秒法则的起源,(39)但是20年的一项研究报告指出,被调查的70%的女性和 5%的男性对五秒法则很熟悉,而且女性比男性更有可能吃掉在地上的食物。

F)那么科学告诉我们地上几秒钟到底对食品安全意味着什么?最早期的对五秒法则的研究报告被认为是 吉利安·克拉克写的————她是一名参加伊利诺斯大学的一项研究项目的高中生。克拉克和她的同事们把细菌 注入到地砖上,然后把饼干放在地砖上持续不同的时间长度。(36)她们的报告指出细菌在五秒之内从地砖转 移到了饼于上,但是并未指出从地砖到饼干上的具体细菌量。

G)但是到底在五秒之内转移了多少细菌呢?在2007年,我在克菜姆森大学的实验室在《应用微生物学杂 志》上发表了一项研究。我们想知道食物接触被污染的表面的时间长度是否影响了细菌转移到食物上的选率。 为了查明真相,我们把细菌注入到方砖、地毯或木制品上。五分钟后,我们把培根肉或面包放在表面上5秒、30 秒或60秒,然后测算转移到食物上的细菌量。在细菌分别停留在表面上2小时、4小时、8小时和24小时后,我 们精确重复了这个过程。

H)(45)我们发现转移到任何一种食物上的细菌数量并不那么取决于食物接触被污染表面的时间长 短————不管是几秒钟还是整个一分钟。在这个表面上的细菌总数起到更大的作用,而且在开始注入细菌后,这 个数量会随着时间的流逝而减少。看上去问题的焦点更少在于食物停留在地上的时间长短,而更多在于那片地 上到底被细菌污染到什么程度。

I)我们还发现,接触表面的种类也会有不同的影响。比如,地毯和木制品、瓷砖相比,似乎是一个相对更好 点的掉落食物的地方。当地毯被污染时,少于1%的细菌会被转移。但是,当食物接触到瓷砖或木制品时 48%到70%的细菌会被转移。

J)去年,英国阿斯顿大学的一项研究使用了和我们的研究几乎一样的参数并得出了相似的结论。他们的报 告也指出87%的受访者会吃或吃过掉在地上的食物。

K)那么你会吃掉在地上的食物吗?从食品安全的角度考虑,如果地面上有几百万个甚至更多的细菌,其中 0.1%的量就足以使你生病。(44)而且,某些种类的细菌极为有害,只需要一点点就可以让你生病。比如,十个 或更少的某种尤其致命的细菌就能导致免疫系统缺乏抵抗力的人患上严重的疾病甚至死亡。但是这类细菌停 留在大多数物体表面的可能性是很低的。

L)(38)而且也不仅仅是把食物拌在地上就会引起细菌污来。细菌会被各种不同的“媒介”携带包括生的 食物、留有细菌的潮温表面、我们的双手和皮肤以及喊嗽和打喷嚏。双手、食物和器皿会携带个别生存在保护性 薄膜下的细菌。这些微小的能够承载细菌的薄层被称为生物薄膜,它们常见于大多数表面上和物体上。生物薄 膜组织可以让细菌停留更长时间,而且很难被清除掉。和依赖自身的细菌相比,在这些组织里的细菌还对清洁 剂和抗生素有更强的抵抗力。

M)(42)所以下次当你考虑吃在地上的食物时,对你有利的可能性是吃后你也不会生病。但是也有极 少的可能是,就在你掉落食物的地方,存在的微生物组织会使你患病,你可以非常确定虫子就在你即将放入嘴里 的食物上。

N)(41)研究或常识告诉我们最好的方法是,让你的双手、器皿和其他任何表面保持千净。

详解详析

36. A research project found bacteria made their way to the food on the floor in five seconds.

(译文)一个研究项目发现细菌能够 在五秒内移动到地上的食物上。

(定位)由题干中的 a research project、bacteria 和 in five seconds 位到文章F)段画线处。

F) So what does science tell us about what a few moments on the floor means for the safety of your food? The earliest research report on the five-second rule is attributed to Jillian Clarke, a high school student participating in a research project at the University of Illinois. Clarke and her colleagues introduced bacteria to floor tiles(瓷砖) and then placed cookies on the tiles for varying times. They reported bacteria were transferred from the tiles to the cookies within five seconds, but didn't report the specific amount of bacteria that made it from the tiles to the food.

(详解) F)段最后一句提到了最早期的对五秒法则的研究报告。她们的报告指出细菌在五秒之内从地砖转 移到饼干上。题干中指出的细菌能够在五秒内移动到地上的食物上是对原文的同义转述,故答案为F)。

37. Whether food is contaminated depends much on the number of bacteria that get onto it.

(译文)食物是否被污染很大程度 上取决于到达其上面的细菌数量。

(定位)由题干中的 depends much the number of bacteria定位到文 章C)段画线处。

C) So is five seconds on the floor the critical threshold (门槛) that separates a piece of eatable food from a case of food poisoning? It's a bit more complicated than that. It depends on just how many bacteria can make it from floor to food in a few seconds and just how dirty the floor is.

(详解) C)段定位句指出,这(指食物是否被污染)取决于有多少细菌会在几秒内从地上到达食物上以及地 面到底有多脏。题干中的 the number of bacteria that get onto it与原文中的 how many bacteria can make it from floor to food属于同义转述,故答案为C)。

38. Food contamination may result from various factors other than food dropping on the floor.

(译文)除了掉在地上的食物以 外,各种不同的因素也可能导致食 物污染。

(定位)由题干中的food contamination和 result from定位 到文章L)段画线处。

L) And it's not just dropping food on the floor that can lead to bacterial contamination. Bacteria are carried by various "media", which can include raw food, moist surfaces where bacteria have been left, our hands or skin and from coughing or sneezing(打喷嚏). Hands, foods and utensils(器皿) can carry individual bacteria living in communities contained within a protective film. These microscopic layers of deposits containing bacteria are known as biofilms and they are found on most surfaces and objects. Biofilm communities can harbor bacteria longer and are very difficult clean. Bacteria in these communities also have an enhanced resistance to sanitizers(清洁剂)and antibiotics compared to bacteria living on their own.

(详解)题干是关于食物污染的起因,由定位句中的 lead to bacterial contamination可推断L)段是在探时 什么因素导致了食物被细菌污染的问题。定位句指出,不仅仅是把食物掉在地上就会引起细菌污染,细菌 被各种不同的“媒介”携带,这与题干的内容相同,故答案为L)。

39. Males are less likely than females to eat food that may have been contaminated.

(译文)男性和女性相比,有更 小的可能性去吃被污染的食物。

(定位)由题干中的 males和 females定位到文章E)段画线处。

E) In fact it was a potato pancake, and it fell on the stovetop, not on the floor. Child put it back in the pan,saying,"But you can always pick it up and if you're alone in the kitchen, who's going to see it? "But the misremembered story persists. It's harder to pin down the origins of the oft-quoted five-second rule. but a 2003 study reported that 70% of women and 56% of men surveyed were familiar with the five-second rule and that women were more likely than men to eat food that had dropped on the floor.

(详解)根据定位句的含义,200年的一项研究报告指出,女性比男性更有可能吃掉在地上的食物。题于中 的 food that may have been contaminated和原文中的 food that had dropped on the floor属于同义转述,面 题干中的 males are less likely than females和原文中的 women were more likely than men也属于同义转述, 故答案为E)。

40. The authors research centers around how food gets contaminated.

(译文)作者的研究围绕食物如何被污 染而展开。

(定位)由题干中的 the author's research Fn how food gets contaminated 定位到文章A)段画线处。

A) When you drop a piece of food on the floor, is it really OK to eat if you pick it up within five seconds? An urban food myth contends that if food spends just a few seconds on the floor, dirt and germs won't have much of a chance to contaminate it. Research in my lab has focused on how food becomes contaminated, and we've done some work on this particular piece of wisdom.

(详解) A)段定位句指出,作者的实验室的研究关注食物是如何被污染的。题干中的 centers around和定 位句中的 focused on是同义转述,且后面宾语内容一致,故答案为A)。

41. Keeping everything clean is the best way to stay healthy.

译文)让所有事物保持干净是保持健康的最好途径。

(定位)由题干中的 keeping everything clean和the best way to stay healthy定位到文章N)段。

N) Research or common sense tells us that the best thing to do is keep your hands, utensils and other surfaces clean.

(详解) 结合上几段内容,作者一直在谈论如何远离疾病、保持健康的方法,而定位段指出,最好的方法是,让 你的双手、器皿和其他任何表面保持干净,这与题干所述内容一致,故答案为N)。

42. Chances are you will not fall sick because of eating food picked up from the floor.

(译文)你有可能不会因为吃从地上捡起 的食物而患病。

(定位)由题干中的 chances和 not fall sick定位到文章M)段画线处。

M) So the next time you consider eating fallen food, the odds are in your favor that you can eat it without getting sick. But in the rare chance that there is a micro-organism that can make you sick on the exact spot where the food dropped, you can be fairly sure that the bug is on the food you are about to put in your mouth.

(详解)定位句中的假设是吃掉在地上的食物后你不会生病,但是也提到了只是有一定的可能性。题于中的 ances和原文中的odds是近义词,题于中的 will not fall sick和原文中的 without getting sick是同义转述 故答案为M)。

43. For a long time people have had the experience of deciding whether or not to eat food picked up from the floor.

(译文)长时间以来,人们都有决定是否 吃从地上捡起的食物的经历。

(定位)由题干中的 experience和 whether or not to eat food picked up from the floor定位到文章D)段画线处。

D) Wondering if food is still OK to eat after it's dropped on the floor is a pretty common experience. And it's probably not a new one either. A well-known, but inaccurate, story about Julia Child may have contributed to this food myth. Some viewers of her cooking show, The French Chef, insist they saw Child drop lamb on the floor and pick it up, with the advice that if they were alone in the kitchen, their guests would never know.

(详解)根据定位句的含义,想知道食物在掉到地上之后是否可以食用是一个很普遍的经历,同时可能也不 是什么新鲜事了。原文中的 a pretty common experience和 not a new one即表示人们都有的一个很普遍的 经历,并不是什么新鲜事了, 这与题干中的 for a long time people have had the experience含义相同,故答案为D)。

44. Some strains of bacteria are so harmful that a tiny few can have deadly consequences.

译文)某些菌种如此有害,以 至于极少量就可以带来致命的 后果。

(定位)由题干中的 harmful和 deadly consequences定位到文章 K)段画线处。

K) Should you eat food fallen on the floor then? From a food safety standpoint, if you have millions or more bacteria on a surface, 0.1% is still enough to make you sick. Also, certain types of bacteria are extremely harmful, and it takes only a small number to make you sick. For example, 10 bacteria or less of an especially deadly strain of bacteria can cause severe illness and death in people with compromised immune systems. But the chance of these bacteria being on most surfaces is very low.

(详解)根据K)段定位句,某些种类的细菌极为有害,只需要一点点就可以让你生病。接着举例说明,十个 或更少的某种尤其致命的细菌就能导致免疫系统缺乏抵抗力的人患上严重的疾病甚至死亡。题干是对原文 的概述,故答案为K)。

45. Researchers found how many bacteria got onto the food did not have much to do with how long the food stayed on a contaminated floor.

(译文)研究者们发现到达食物上的细菌量 与食物在被污染的地面上停留的时间长短并 无太大关系。

(定位)由题干中的 bacteria got onto the food 和 how long the food stayed on a contaminated floor定位到文章H)段画线处。

H) We found that the number of bacteria transferred to either kind of food didn't depend much on how long the food was in contact with the contaminated surface——whether for a few seconds or for a whole minute. The overall number of bacteria on the surface mattered more. and this decreased over time after the initial introduction. It looks like what's at issue is less how long your food stays on the floor and much more how contaminated with bacteria that patch of floor happens to be.

(详解) H)段定位句指出,我们发现转移到任何一种食物上的细菌数量并不那么取决于食物接触被污染表 面的时间长短,题于中的 stayed on和定位句中的 was in contact with是同义转述,且结论一致,故答案为H)。