2016年职称英语等级考试教材_理工类新增文章

清枫月

Primer on Smell

In addition to bringing out1 the flavor of food, what does the sense of smell do for us?
Smell “gives us information about place, about where we are,” says Randall Reed, a Johns Hopkins University professor whose specialty is the sense of smell. ___1___ “Whether we realize it or not, we collect a lot of information about who is around us based on smell,” says Reed.
Even at a distance, odors can warn us of2 trouble — spoiled food, leaking gas, or fire. “It’s a great alert,” offers Donald Leopold, a doctor at Johns Hopkins. For example, if something in the oven is burning, everyone in the house knows it.
With just a simple scent, smell can also evoke very intense emotion. Let’s say, for example, that the smell is purple petunias. ___2___ Now let’s imagine that your mother died when you were three, and she used to have a flower garden. You wouldn’t need to identify the smell or to have conscious memories of your mother or her garden. You would feel sad as soon as you smelled that spicy odor.
Compared with3 animals, how well do people detect smelts?
That depends on what you mean by “how well”. We are low on receptor cells ： current estimates say that humans have roughly five million smell-receptor cells, about as many as a mouse. ___3___
Reed says that, across species, there is a relatively good correlation between the number of receptor cells and how strong the sense of smell is. “You can hardly find the olfactory bulb in a human brain —— it’s a pea-sized object. In a mouse, it’s a little bigger. It’s bean-sized in a rat, about the size of your little finger in a rabbit, and the size of your thumb in a bloodhound.”
Does that mean that our sense of smell is not very acute?
Not exactly. While we may not have the olfactory range of other creatures, the receptors we do have are as sensitive as those of any animal. ___4___ A trained “nose”, such as that of a professional in the perfume business, can name and distinguish about 10,000 odors. Reed says that a perfume expert can sniff a modem scent that has a hundred different odorants in it, go into the lab, and list the ingredients. “In a modest amount of time, he comes back with what to you or me would smell like a perfect imitation of that perfume. It’s amazing.”
What happens to4 our sense of smell as we age?
Many people continue to have good olfactory function as they get older. ___5___ Leopold says that smell is generally highest in childhood, stays the same from the teens through the 50s, and drops starting at about 60 for women and 65 for men. “The average 80-year-old is only able to smell things half as well as the average 20-year-old,” says Leopold.

词汇：
scent /sent/ n. 气味，香味
petunia /pə'tju:niə/ n. 喇叭花
olfactory /ɔl'fækt(ə)ri/ adj. 嗔觉的，味道的
sniff /snif/ v. 嗅，闻，用力吸

注释：
1.    bring out：使……显出，使……变得明显
2.    warn of：发出关于……的警告。warn sb. of sth.：警告某人某事
3.    compare with：与……相比
4.    happen to：发生于，发生在

练习：
A    These flowers have a rich spiciness that no other petunia has.
B    Odors, or smells, can warn us about trouble.
C    That’s not the rule, however.
D    And smell tells us about people.
E    We can also think, and we make conscious (and successful) efforts to tell the difference between one smell and another.
F    A rat has some 10 million, a rabbit 20 million, and a bloodhound 100 million.

答案与题解：
1.    D  根据后文提到的“我们能够根据气味收集到有关人的很多信息”可以推断此处答案是D选项。
2.    A  前文提到以紫喇叭花的香味举例，选项中只有A选项提到了喇叭花。
3.    F  前文提到人类和小鼠的嗅觉受体细胞数量，可以推断此处应介绍其他物种的嗅觉受体细胞数量。
4.    E  后文都在介绍人类可以区分味道的不同，所以此处E选项最符合原文意思。
5.    C  后文介绍了不是每个人都随着年龄的增长嗅觉能力不发生变化，所以此处C选项最符合原文。