历年真题精析——命题剖析及复习指导(6)

Section I Use of English

Directions:
Read the following text. Choose the best word(s) for each numbered blank and mark A,B,C or D on ANSWER SHEET 1.(10 points)

The human nose is an underrated tool. Humans are often thought to be insensitive smeller compared with animals,1 this is largely because,2 animals, we stand upright. This means that our noses are 3 to perceiving those smells which float through the air, 4 the majority of smells which stick to surfaces. In fact 5, we are extremely sensitive to smells,6 we do not generally realize it. Our noses are capable of 7 human smells even when these are 8 to far below one part in one million.

Strangely, some people find that they can smell one type of flower but not another, 9 others are sensitive to the smells of both flowers. This may be because some people do not have the genes necessary to generate 10 smell receptors in the nose. These receptors are the cells which sense smells and send 11 to the brain. However, it has been found that even people insensitive to a certain smell 12 can suddenly become sensitive to it when 13 to it often enough.

The explanation for insensitivity to smell seems to be that brain finds it 14 to keep all smell receptors working all the time but can 15 new receptors if necessary. This may 16 explain why we are not usually sensitive to our own smells-we simply do not need to be .We are not 17 of the usual smell of our own house but we 18 new smells when we visit someone else's. The brain finds it best to keep smell receptors 19 for unfamiliar and emergency signals 20 the smell of smoke, which might indicate the danger of fire.

人类鼻子的功能常常被低估了。人们常认为，与动物相比，人类的嗅觉是迟钝的，而这在很大程度上是因为人类是直立的，这一点与动物不同。这就意味着我们的鼻子仅限于去感知空气中飘过的气味，而大部分的气味是附着的各种物体表面的，就被我们错过了。然而，事实上我们的嗅觉是十分敏感的，尽管我们通常都没有意识到这一点。即使当这些气味被冲淡到不及原来的百万分之一，我们的鼻子也能够分辨出不同的人类气味。

奇怪的是，有些人发现他们可以闻出一种花香，却闻不出另一种，而有些人却对两种花香都很敏感。这可能是因为有些人缺少某种基因，这种基因正好用于产生鼻子里对某种味道的感受器。这些感受器是由一些能感知气味并把信息传递给大脑的细胞构成。然而，研究发现即使人们最开始对某种气味不敏感，但当人们经常闻到这种气味后就能突然对它很敏感。

对气味的不敏感似乎可以这样解释，大脑发现让所有的气味感受器一直工作效率会很低，但可以在需要的时候触发新的接受器。这也可以解释为什么我们通常对自身的各种气味不敏感--只不过我们不需要这样做。我们不会觉察到我们自己房子的熟悉气味，但当我们拜访别人家时，就会注意到我们不熟悉的气味。大脑会使气味感受器可用于随时接受不熟悉的和紧急的信号，例如烟的气味，因为它可能意味着有着火的危险。

1. [A] although [B] as [C] but [D] while

2. [A] above [B] unlike [C] excluding [D] besides

3. [A] limited [B] committed [C] dedicated [D] confined

4. [A] catching [B] ignoring [C] missing [D] tracking

5. [A] anyway [B] though [C] instead [D] therefore

6. [A] even if [B] if only [C] only if [D] as if

7. [A] distinguishing [B] discovering [C] determining [D] detecting

8. [A] diluted [B] dissolved [C] dispersed [D] diffused

9. [A] when [B] since [C] for [D] whereas

10. [A] unusual [B] particular [C] unique [D] typical

11. [A] signs [B] stimuli [C] messages [D] impulses

12. [A] at first [B] at all [C] at large [D] at times

13. [A] subjected [B] left [C] drawn [D] exposed

14. [A] ineffective [B] incompetent [C] inefficient [D] insufficient

15. [A] introduce [B] summon [C] trigger [D] create

16. [A] still [B] also [C] otherwise [D] nevertheless

17. [A] sure [B] sick [C] aware [D] tired

18. [A] tolerate [B] repel[C] neglect [D] notice

19. [A] available [B] reliable [C] identifiable [D] suitable

20. [A] similar to [B] such as[C] along with[D] aside from

[内容提要]

人类的鼻子一直被低估了。基因能在鼻子里生成针对某种气味的感受器，以及对一些气味不敏感的原因。

1.[正确答案]C

[考查重点] 逻辑衔接

[解题过程] Humans are often thought to be insensitive smellers compared with animals, this is largely because,   animals, we stand upright. "人们常常认为，与动物相比，人类的嗅觉不够敏锐，......而这在很大程度上是因为人类直立行走，这一点与动物......。"although 表示让步；. as表示时间或者原因； but表示转折关系； while 表示时间或者对比。四个选项中，but是表示转折的并列连词，but后面的内容是语句重心所在。While也可以表示对比、转折，但作为从属连词也有让步含义。从本题前后的语义关系来看，后半句语义应当是重心所在。因此，正确答案为C。

2.[正确答案]B

[考查重点] 语义衔接

[解题过程]...this is largely because,   animals, we stand upright. "而这在很大程度上是因为人类直立行走，这一点与动物......" 人类直立行走，而动物却不同。因此，正确答案为B。

3.[正确答案]A

[考查重点] 语义衔接/ 词汇辨析

[解题过程] This means that our noses are   3   to perceiving those smells which float through the air. "这意味着我们的鼻子......闻到漂浮在空气中的气味。"选项A. be limited to 被限制在......；B. be committed to 被交给......,答应承担......义务；C. be dedicated to 奉献，献给；D. be confined to 限制在，局限于。根据句意可以排除B、C项。be confined to有"把......局限/限制于"的含义，但是它一般用于具体范围的"局限、限制"，与句子的语境不符。因此，正确答案为A。

4.[正确答案]C

[考查重点] 语义衔接

[解题过程] 本题目选择介词或者现在分词，将前面的句子和后面的名词连接到一起，体现紧密的逻辑关系。句子叙述到This means that our noses are limited to perceiving those smells which float through the air, the majority of smells which stick to surfaces. "这意味着我们的鼻子只能闻到漂浮在空气中的气味，......大多数在地表附近的气味。"不难发现，人类闻到的气味有限，没有闻到的地表的气味很多。选项A. catching 抓住；B. ignoring 忽略；C. missing 错过；D. tracking 跟踪，追溯。前面说我们的鼻子只能闻到浮在空气中的气味，对于大部分停留在表面的气味当然是"闻不到"。首先可以排除A、D项，ignore含有"有意不......"的意思，显然不符合语境。故正确答案为C。

5.[正确答案]B

[考查重点] 逻辑衔接

[解题过程] In fact, we are extremely sensitive to smells, we do not generally realize it. 由于本句中的in fact提示了转折关系，因此要选择转折的逻辑关系词。选项A. anyway 无论如何（表示让步）；B. though 虽然（表示让步或转折）；C. instead 相反；D. therefore 因此（表示结果）。四个选项中，只有though能与in fact连用表示转折（不过，事实上......）。因此，正确答案为B。

6.[正确答案]A

[考查重点] 逻辑衔接

[解题过程] In fact though, we are extremely sensitive to smells,     we do not generally realize it. "事实上，我们对气味极其敏感，......我们一般没有意识到。" 选项A. even if 即使（表让步）；B. if only 但愿（后常接虚拟语气，表示愿望）；C. only if 如果（用于表达条件关系，only表强调）；D. as if 似乎（用于表达比较关系）。四个选项中只有A项 even if 用于表达让步关系"即使"。因此，正确答案为A。

7.[正确答案]D

[考查重点] 语义衔接/词汇辨析

[解题过程] 本题目选择动名词，在句子中充当谓语的动作内容。句子叙述到Our noses are capable of...      human smells "我们的鼻子能够......人的气味"。选择谓语动词，主语和宾语提供信息决定答案。选项A. distinguishing 区别；B. discovering 发现；C. determining 决定；D. detecting发现，发觉，感知。我们的鼻子只能是感知（引申为闻到）人的气味"。因此，正确答案为D。

8.[正确答案]A

[考查重点] 语义衔接/ 词汇辨析

[解题过程] 本题目选择动词过去分词形式，构成 "be...to "的短语。Our noses are capable of detecting human smells even when these are    to far below one part in one million. "我们的鼻子能够闻到人的气味，即使这些气味被......到百万分之一。" 选项A. diluted 稀释的（可以用在液体或气体的稀释）；B. dissolved 溶解(通常指固体溶解为液体)；C. dispersed 散开；D. diffused 扩散，弥漫。气味应该是被稀释或冲淡到百万分之一。因此，正确答案为A。

9.[正确答案]D

[考查重点] 逻辑衔接

[解题过程] Strangely, some people find that they can smell one type of flower but not another,  others are sensitive to the smells of both flowers. "奇怪的是，有些人发现他们可以闻到一种花香，却闻不出另一种，......有些人却对两种花香都很敏感。" 显然构成一种对比关系，只有whereas能用于引导表示转折关系的并列句。因此，正确答案为D。

10.[正确答案]B

[考查重点] 词汇辨析

[解题过程] 本题目选择形容词，修饰后面的名词。句子叙述到This may be because some people do not have the genes necessary to generate smell receptors in the nose. "这意味着有些人的鼻子里缺少某种基因，这种基因是激发人鼻子里的......气味感知器所必需的。"选项A. unusual 不寻常的；B. particular 特别的，特定的；C. unique 独一无二的；D. typical 典型的。这种"气味感知器"具有感知气味这种特定的功能。因此，正确答案为B。

11.[正确答案]C

[考查重点] 语义衔接

[解题过程] 本题目选择名词。句子叙述到These receptors are the cells which sense smells and send  to the brain. "这些感知器是一种细胞。这种细胞能够感知气味，并且向大脑传递......"选项A. signs 标记；B. stimuli　刺激；C. messages 信息，信号；D. impulses 冲动，推动。身体的各个器官向大脑传递的是信号。因此，正确答案为C。（补充：人体的每个器官附近都密布着神经末梢。在感受到外界刺激时，神经末梢紧张起来处理外界刺激转换成大脑能够辨认的信号，并将这些信号迅速传递给大脑。）

12.[正确答案]A

[考查重点] 语义衔接

[解题过程] However, it has been found that even people insensitive to a certain smell can suddenly become sensitive to it "然而，......对某种特定气味不敏感的人也能突然变得敏感起来。"在本句中，供选的状语修饰整个句子。选项A. at first 起初；B. at all 根本；C. at large 全面地，详细地，无拘无束地; D. at times 有时。由于谓语部分的频度状语"突然"体现了时间的交替关系，句子应该表达起初不敏感。因此，正确答案为A。

13.[正确答案]D

[考查重点] 语义衔接

[解题过程] even people insensitive to a certain smell at first can suddenly become sensitive to it when  13  to it often enough. "然而，起初对某种特定气味不敏感的人也会突然变得敏感起来，当他们经常......在这种气味中时。"选项A. be subjected to 遭受，屈服于；B. be left to 被留给......；C. be drawn to 被拖到......；D. be exposed to 暴露在......（经常接触）。语境表达的是人处于某种气味所笼罩的环境中。因此，正确答案为D。

14.[正确答案]C

[考查重点] 语义衔接/词汇辨析

[解题过程] The explanation for insensitivity to smell seems to be that brain finds it  to keep all smell receptors working all the time "认为鼻子不敏感的解释表明：大脑发现让所有的气味感知器一直处于工作状态是......的。" 选项A. ineffective 无效的，不起作用的；B. incompetent 不能胜任的；C. inefficient 效率低的；D. insufficient 不足的，不够的。根据语境，首先可以排除B、D项。ineffective 和 inefficient一个强调效果，一个强调效率。大脑发现让所有的气味感知器一直处于工作状态会使气味感知器的效率降低。因此，正确答案为C。

15.[正确答案]D

[考查重点] 语义衔接

[解题过程] The explanation for insensitivity to smell seems to be that brain finds it inefficient to keep all smell receptors working all the time but can new receptors if necessary. "认为鼻子不敏感的解释表明：大脑发现让所有的气味感知器一直处于工作状态是效率低的。但是，需要时又可以......新的气味感知器。" 选项A. introduce 介绍，引进；B. summon 呼唤，号召；C. trigger 扣动扳机，一触即发；D. create 创造，产生（从无到有）。trigger the receptors"激活受体"是常见的搭配，但"激活"应该是对现已存在的食物而言。从空格后面的new来判断，只有create才符合逻辑。因此，正确答案为D。

16.[正确答案]B

[考查重点] 逻辑衔接

[解题过程] This may explain why we are not usually sensitive to our own smells-we simply do not need to be . "这......可以解释为什么我们通常对自己的气味不敏感--我们根本不需要（对自己的气味敏感）。"选项A. still 仍然；B. also 也；C. otherwise 否则；D. nevertheless 然而，虽然如此。"this"这个词就表明了逻辑关系应该是并列，翻译成"也"，表示和前面的句子是相同或者相近的含义。因此，正确答案为B。

17.[正确答案]C

[考查重点] 语义衔接

[解题过程] 本题目选择 "be not...of "的结构，在句子中充当位于动词。句子叙述到We are not of the usual smell of our own house "一般我们没有......我们自己房间里的气味。" 此句的意思是：我们意识不到自己家里的气味，但当我们去拜访他人时就会留意到新的气味。因此，选aware of。 sure of "确信"，sick of "厌倦"，tired of "厌倦"都不合句意。

18.[正确答案]D

[考查重点] 语义衔接

[解题过程] We are not aware of the usual smell of our own house but we new smells when we visit someone else's.  "我们意识不到自己家里的气味。但是，在拜访别人家时，我们......新的气味。"选项A. tolerate 忍受；B. repel 抵制；C. neglect 忽略；D. notice 注意到。句子中的 "but"提供了信息，前后两个句子含义相反。前面提到"没有注意到自己房间的气味"，后面就应该是闻到新的气味。因此，正确答案为D。

19.[正确答案]A

[考查重点]  语义衔接

[解题过程] The brain finds it best to keep smell receptorsfor unfamiliar and emergency signals "大脑会使气味感知器......随时接受不熟悉的和紧急的信号"。选项A. available 可达到的，可工作的；B. reliable 可靠的；C. identifiable 可辨认的；D. suitable 适合的。 "大脑会使气味感知器工作来处理随时接受不熟悉和紧急信号"，故选available，符合句子含义。

20.[正确答案]B

[考查重点] 语义衔接

[解题过程] The brain finds it best to keep smell receptors available for unfamiliar and emergency signals the smell of smoke, which might indicate the danger of fire.  "大脑会使气味感知器用于随时接受不熟悉的和紧急的信号，......烟的气味，因为预示着着火的危险"。选项A. similar to 相似于；B. such as 例如；C. along with 和......一起；D. aside from 除......之外。烟的气味恰恰被包含在前面相邻的"不熟悉和紧急信号"之中，应该选择表示列举意义的短语。因此，正确答案为B。