Before microscopes were first used in the seventeenth century, no one knew that living organisms were composed of cells. The first microscopes were light microscopes, which work by passingvisiblelight through aspecimen. Glass lenses in themicroscopebend the light tomagnifytheimageof thespecimenandprojecttheimageinto the viewer's eye or ontophotographicfilm. Light microscopes canmagnifyobjects up to 1,000 times without causing blurriness.

Magnification, the increase in theapparentsize of an object, is one important factor in microscopy. Also important is resolving power, ameasureof the clarity of animage. Resolving power is theabilityof anopticalinstrumentto show two objects asseparate. For example, what looks to theunaidedeye like a single star in the sky may be resolved as two stars with the help of atelescope. Anyopticaldeviceis limited by its resolving power. The lightmicroscopecannotresolvedetailfiner than 0.2 micrometers, about the size of the smallest bacterium;consequently, no matter how many times itsimageof such a bacterium is magnified, the lightmicroscopecannot show the details of thecell'sinternalstructure.

From the year 1665, when English microscopist Robert Hooke discovered cells, until the middle of the twentieth century, biologists had only light microscopes for viewing cells. But they discovered a greatdeal, including the cells composing animal and plant tissues,microscopicorganisms, and some of the structures within cells. By the mid-1800s, these discoveries led to thecelltheory, which states that all living things are composed of cells and that all cells come from other cells.

Our knowledge ofcellstructure took agiantleapforwardas biologists began using theelectronmicroscopein the 1950s. Insteadof light, theelectronmicroscopeuses abeamof electrons and has a much higher resolving power than the lightmicroscope. In fact, the most powerful modernelectronmicroscopes candistinguishobjects as small as 0.2 nanometers, a thousandfold improvement over the lightmicroscope. The period at the end of this sentence is about a million times bigger than an object 0.2 nanometers indiameter, which is the size of a largeatom. Only underspecialconditions canelectronmicroscopesdetectindividualatoms. However, cells, cellular organelles, and even molecules like DNA andproteinare much larger than single atoms.

Biologists use the scanningelectronmicroscopeto study the detailedarchitectureofcellsurfaces. It uses anelectronbeamtoscanthe surface of acellor group of cells that have been coated with metal. The metal stops thebeamfrom going through the cells. When the metal is hit by thebeam, it emits electrons. The electrons are focused to form animageof the outside of the cells. The scanningelectronmicroscopeproduces images that look three-dimensional.

The transmissionelectronmicroscope, on the other hands, is used to study the details ofinternalcellstructure. Specimens are cut into extremely thin sections, and the transmissionelectronmicroscopeaims anelectronbeamthrough asection, just as a lightmicroscopeaims abeamof light through aspecimen. However,insteadof lenses made of glass, the transmissionelectronmicroscopeuses electromagnets as lenses, as do allelectronmicroscopes. The electromagnets bend theelectronbeamtomagnifyandfocusanimageonto a viewingscreenorphotographicfilm.

Electronmicroscopes have truly revolutionized the study of cells andcellorganelles. Nonetheless, they have not replaced the lightmicroscope. One problem withelectronmicroscopes is that they cannot be used to study living specimens because thespecimenmust be held in avacuumchamber; that is, all the air andliquidmust be removed. For a biologist studying a livingprocess, such as the whirling movement of a bacterium, a lightmicroscopeequipped with a video camera might be better than either a scanningelectronmicroscopeor a transmissionelectronmicroscope. Thus, the lightmicroscoperemains a useful tool, especially for studying living cells. The size of acelloften determines the type ofmicroscopea biologist uses to study it.

Questions:
question_stem: According to paragraph 1, what happens to the light when a specimen is being viewed with a light microscope?
choices: tag: A
text: The light continues unchanged directly into the viewer's eye or onto film.

tag: B
text: A glass lens bends the light to form a magnified image of the specimen.

tag: C
text: The light is projected onto photographic film to produce a blurred image.

tag: D
text: The intensity of the light increases a thousand times.
answer_key: B
explanation: 【题目翻译】根据第1段，当用光学显微镜观察样品时，光会发生什么变化？
A：光线继续保持不变，直接进入观众的眼睛或胶片。

B：一个玻璃透镜弯曲光线，形成一个放大的样品图像。

C：光线投射到胶片上，产生模糊的图像。

D：光的强度增加了一千倍。

【判定题型】：题目问的是文章中的具体细节信息，故根据题目问法可以判断本题为事实信息题。

【关键词定位】本题根据 the light，specimen 和 a light microscope 定位到第一段这几句：The first microscopes were light microscopes, which work by passing visible light through a specimen. Glass lenses in the microscope bend the light to magnify the image of the specimen and project the image into the viewer's eye or onto photographic film.意思是“最早的显微镜是光学显微镜，它的工作原理是将可见光通过样品。显微镜中的玻璃透镜弯曲光线以放大样品的图像，并将图像投射到观察者的眼睛或摄影胶片上”。

【逻辑分析】文章讲了光学显微镜的原理，就是折射光以放大标本的图像，并且把图像投射到观察者的眼睛里或者投射到胶卷上。

【选项分析】
A.选项 A 说光不需要折射直接进入人的眼睛，错误；
B.选项 B 符合文章，正确。
C.选项 C 说投射到胶卷上的光形成模糊的影像，从后文我们知道不一定是模糊的，错误；
D.选项 D 说光的强度增加了一千倍，无中生有，错误。

question_stem: Why does the author mention "a telescope" as part of the discussion of microscopes?
choices: tag: A
text: To show how microscopes and telescopes are different.

tag: B
text: To emphasize the importance of magnification in all optical devices.

tag: C
text: To explain how the development of the microscope depended on the invention of the telescope.

tag: D
text: To illustrate the concept of resolving power.
answer_key: D
explanation: 【题目翻译】为什么作者提到“望远镜”作为显微镜讨论的一部分？
A：展示显微镜和望远镜的不同之处。

B：强调放大在所有光学设备中的重要性。

C：解释显微镜的发展如何依赖望远镜的发明。

D：说明分辨力的概念。

【判定题型】：根据题干问法“why …… mention”，题目询问“xxxxxx”(文章引用内容)的修辞目的，可以判断本题为修辞目的题。

【关键词定位】题根据 a telescope 定位到第二段这两句：Resolving power is the ability of an optical instrument to show two objects as separate. For example, what looks to the unaided eye like a single star in the sky may be resolved as two stars with the help of a telescope. 

【引用内容分析】第一句讲 resolving power 是什么，第二句用望远镜类比，帮助读者理解这个概念。

【选项分析】
A.选项 A 说展示显微镜和望远镜的不同，不符原文，错误
B.选项 B 说明光学设施中放大的重要性，不符原文，错误。
C.选项 C 说解释为什么显微镜的发展依赖于望远镜，不符合原文，错误
D.选项 D 正确。

question_stem: Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incorrect choices change the meaning in important ways or leave out essential information.
choices: tag: A
text: A light microscope has the power to greatly magnify a bacterium that is smaller than 0.2 micrometers.

tag: B
text: A light microscope can only resolve objects 0.2 micrometers or larger, so it cannot show the interior form of a cell.

tag: C
text: The smallest bacterium has a complex internal structure that can be seen with a light microscope.

tag: D
text: The greater the magnifying power of a light microscope, the greater its ability to resolve the internal structure of a cell.
answer_key: B
explanation: 【题目翻译】下面哪句话最能表达文章中突出显示的句子中的基本信息？错误的选择会以重要的方式改变意义，或者遗漏重要的信息。
A：光学显微镜有能力大大放大小于0.2微米的细菌。

B：光显微镜只能分辨0.2微米或更大的物体，所以不能显示细胞的内部形态。

C：最小的细菌有一个复杂的内部结构，可以用光学显微镜看到。

D：光学显微镜的放大能力越大，它分解细胞内部结构的能力就越强。

【判定题型】：根据题目问法，题目要求选择和高亮句意思逻辑都最为接近的句子，故判断本题为句子简化题。

【句子分析】本题先找到高亮出来的句子：The light microscope cannot resolve detail finer than 0.2 micrometers, about the size of the smallest bacterium; consequently, no matter how many times its image of such a bacterium is magnified, the light microscope cannot show the details of the cell's internal structure. 这句话主干的意思大致是：光学显微镜的放大倍数有限，到了0.2毫米以后就不能放大细节了，以至于不论它能放大多少倍，我们都看不到细胞内部的细节。

【选项分析】
A.选项 A 说光学显微镜可以看清楚比0.2毫米小的东西，不符，错误。
B.选项 B 说光学显微镜只能看清楚0.2毫米更大的东西，不能展示细胞内部，是本句的同义转述，正确。
C.选项 C 说最小的细菌的内部结构可以被光学显微镜看清，不符，错误。
D.选项 D 说光学显微镜的放大能力越强，看清楚细胞内部结构的能力也越强，不符，错误。

question_stem: What can be inferred from paragraph 3 about the scientific contribution of Robert Hooke?
choices: tag: A
text: His discovery of cells resulted from the examination of animal tissue rather than plant tissue.

tag: B
text: He was the first person to develop and explain cell theory.

tag: C
text: He discovered cells using a light microscope.

tag: D
text: The full significance of his work was first understood in the mid-nineteenth century.
answer_key: C
explanation: 【题目翻译】从第3段可以推断出罗伯特•胡克的科学贡献是什么？
A：他发现细胞的原因是对动物组织而不是植物组织的检查。

B：他是第一个发展和解释细胞理论的人。

C：他用光学显微镜发现了细胞。

D：他的工作的全部意义是在十九世纪中叶第一次被理解的。

【判定题型】：根据题干中出现的关键词“imply”/“infer”/“suggest”等其他表示推断的词，判定本题为推理题。

【关键词定位】本题题干关键词是 Robert Hooke，定位回第三段这一句：From the year 1665, when English microscopist Robert Hooke discovered cells, until the middle of the twentieth century, biologists had only light microscopes for viewing cells. 

【逻辑分析】 本句大意是从1665到20世纪中期，只有光学显微镜。所以在这个时期里的 Robert Hooke 用的也是光学显微镜发现了细胞。

【选项分析】
A.选项 A 原文中都没有提到过，故错误。
B.选项 B 说的 develop 和 explain 原文中也没有提，只是发现。故错误。
C.符合原文，故正确。
D.选项 D 原文中都没有提到过，故错误。

question_stem: The word "giant" in the passage is closest in meaning to
choices: tag: A
text: huge

tag: B
text: expected

tag: C
text: complex

tag: D
text: sudden
answer_key: A
explanation: 【题目翻译】文中“giant”与下列哪一个意思最相近？
选项 A 是巨大的，
选项 B 是期待的，
选项 C 是复杂的，
选项 D 是突然的。

【判定题型】：题目要求选出与高亮单词意思最接近的选项，故判断本题为词汇题。

【关键词定位】：根据关键词“giant”,定位到原句“Our knowledge of cell structure took a giant leap forward as biologists began using the electron microscope in the 1950s.”。

【词汇解析】：词汇“giant”的意思是巨大的”,带入到原句中，原句的意思是“我们对于细胞结构认识的跨越在生物学家在1950年左右开始用电子显微镜后实现了大的跨越”。

【选项分析】
选项 A 是巨大的，同义替换，正确
选项 B 是期待的，不符，错误
选项 C 是复杂的，不符，错误
选项 D 是突然的。不符，错误

question_stem: According to paragraph 4, which of the following is true of electron microscopes?
choices: tag: A
text: They do not use light to magnify and resolve objects.

tag: B
text: They can magnify the internal structure of a single atom.

tag: C
text: Their earliest versions were not significantly more powerful than light microscopes.

tag: D
text: They had to be modified extensively for their use in biology research.
answer_key: A
explanation: 【题目翻译】根据第4段，电子显微镜的下列哪项是正确的？
A：他们不使用光来放大和解析物体。

B：它们可以放大单个原子的内部结构。

C：他们最早的版本并没有比光学显微镜更强大。

D：为了在生物学研究中使用，它们必须进行广泛的修改。

【判定题型】：题目问的是文章中的具体细节信息，故根据题目问法可以判断本题为事实信息题。

【关键词定位】本题需要根据 electron microscope 定位到第四段这一句：Instead of light, the electron microscope uses a beam of electrons and has a much higher resolving power than the light microscope.意思是“电子显微镜使用的不是光，而是一束电子，比光学显微镜有更高的分辨力”。

【逻辑分析】可知，电子显微镜使用一束电子而不是光束，它具有比光学显微镜更高的分辨能力。

【选项分析】
A.选项 A 说电子显微镜不用光束，正确。
B.文中未提及，错误。
C.文中未提及，错误。
D.文中未提及，错误。

question_stem: The word "detect" in the passage is closest in meaning to
choices: tag: A
text: change

tag: B
text: reveal

tag: C
text: combine

tag: D
text: enlarge
answer_key: B
explanation: 【题目翻译】文中“detect”与下列哪一个意思最相近？
选项 A 是改变，
选项 B 是揭露，
选项 C 是结合，
选项 D 是变大。

【判定题型】：题目要求选出与高亮单词意思最接近的选项，故判断本题为词汇题。

【关键词定位】：根据关键词“detect”,定位到原句“Only under special conditions can electron microscopes detect individual atoms.”。

【词汇解析】：词汇“detect”的意思是“探测”,带入到原句中，原句的意思是“只有在特定情况下，电子显微镜才可以探测出单个的原子”。

【选项分析】
选项 A 是改变，不符，错误
选项 B 是揭露，同义替换，正确
选项 C 是结合，不符，错误
选项 D 是变大。不符，错误

question_stem: According to paragraph 5, what is the role of metal in the scanning electron microscope?
choices: tag: A
text: It magnifies the light that passes through the cells.

tag: B
text: It coats the surface of cells with protective cover.

tag: C
text: It enables the production of images showing the surface structure of cells.

tag: D
text: It reveals details hidden underneath the surfaces of cells.
answer_key: C
explanation: 【题目翻译】根据第5段，金属在扫描电子显微镜中的作用是什么？
A：它放大了穿过细胞的光。

B：在电池表面涂上保护层。

C：它可以生成显示细胞表面结构的图像。

D：它揭示了隐藏在细胞表面下面的细节。

【判定题型】：题目问的是文章中的具体细节信息，故根据题目问法可以判断本题为事实信息题。

【关键词定位】本题题干给出的关键词是 the role of metal 和 scanning electron microscope，根据这两个短语定位到第五段中间的两句话：It uses an electron beam to scan the surface of a cell or group of cells that have been coated with metal. The metal stops the beam from going through the cells. When the metal is hit by the beam, it emits electrons. The electrons are focused to form an image of the outside of the cells. The scanning electron microscope produces images that look three-dimensional. 
意思是“电子显微镜用一束电子来扫描细胞表面，细胞表面是被一层金属包裹的。这层金属表面阻止了电子束穿过细胞。这层金属层可以反射电子，形成细胞外层的三维图像”。

【逻辑分析】可知，这层金属的作用是帮助电子显微镜成像。

【选项分析】
A.选项 A 说可以放大像，不符，错误
B.选项 B 说可以作为保护层，不符，错误
C.符合原意，正确
D.选项 D 说可以揭示细胞内部细节，不符，错误

question_stem: The word "emits" in the passage is closest in meaning to
choices: tag: A
text: transfers

tag: B
text: excites

tag: C
text: sends out

tag: D
text: speeds up
answer_key: C
explanation: 【题目翻译】文中“emits”与下列哪一个意思最相近？
选项 A 的意思是转化，
选项 B 的意思是使激动，
选项 C 的意思是发射，放出，
选项 D 的意思是加速。

【判定题型】：题目要求选出与高亮单词意思最接近的选项，故判断本题为词汇题。

【关键词定位】：根据关键词“emits”,定位到原句“：When the metal is hit by the beam, it emits electrons.”。

【词汇解析】：词汇“emits”的意思是放射，发出,带入到原句中，原句的意思是“当电子束被金属击中时，会放射出电子”。

【选项分析】
选项 A 的意思是转化，不符，错误
选项 B 的意思是使激动，不符，错误
选项 C 的意思是发射，放出，同义替换，正确
选项 D 的意思是加速。不符，错误

question_stem: According to paragraphs 5 and 6, the transmission electron microscope differs from the scanning electron microscope in all of the following ways EXCEPT
choices: tag: A
text: Specimens viewed by transmission electron microscopes are divided into cross sections.

tag: B
text: The transmission electron microscope uses electromagnets as lenses.

tag: C
text: The transmission electron microscope passes an electron beam through a specimen.

tag: D
text: The transmission electron microscope focuses on the inner structure of a cell.
answer_key: B
explanation: 【题目翻译】根据第5段和第6段，透射电子显微镜与扫描电子显微镜在以下所有方面都不同，除了
A：用透射电子显微镜观察的标本被分成横截面。

B：透射电子显微镜用电磁铁作透镜。

C：透射电子显微镜将电子束穿过样品。

D：透射电子显微镜聚焦于细胞的内部结构。

2、【判定题型】：根据题干中出现的大写“EXCEPT”/"NOT" 等其他明显表示否定的词，可以判定本题为否定事实信息题，需要找出与原文信息不符的那个答案。

【关键词定位】题干给的关键词是 differ from 和两种显微镜 transmission electron microscope，scanning electron microscope,可以将出题范围锁定在 Passage 5和6。

【选项分析】
A.选项 A 的依据是 Specimens are cut into extremely thin sections，正确；
B.选项 B 的依据是 the transmission electron microscope uses electromagnets as lenses, as do all electron microscopes，选项 B 错误，因为不是 differ from 的点，而是相同的点；
C.选项 C 的依据是 a light microscope aims a beam of light through a specimen，正确；
D.选项 D 的依据是 is used to study the details of internal cell structure，正确。

question_stem: The word "Nonetheless" in the passage is closest in meaning to
choices: tag: A
text: Basically

tag: B
text: In a way

tag: C
text: In addition

tag: D
text: However
answer_key: D
explanation: 【题目翻译】文中“Nonetheless”与下列哪一个意思最相近？
选项 A 是基本上，
选项 B 是在某种程度上，
选项 C 是还有，
选项 D 是然而。

【判定题型】：题目要求选出与高亮单词意思最接近的选项，故判断本题为词汇题。

【关键词定位】：根据关键词“Nonetheless”,定位到原句：Electron microscopes have truly revolutionized the study of cells and cell organelles. Nonetheless, they have not replaced the light microscope.

【词汇解析】：词汇“Nonetheless”的意思是然而，表转折，带入到原句中，原句的意思是“电子显微镜的确改革了细胞和细胞器的研究。然而，它们并不能代替光学显微镜”。

【选项分析】
选项 A 是基本上，不符，错误
选项 B 是在某种程度上，不符，错误
选项 C 是还有，不符，错误
选项 D 是然而。同义替换，正确