2021贵州考研英语考试真题卷.docx
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1、2021贵州考研英语考试真题卷本卷共分为1大题50小题,作答时间为180分钟,总分100分,60分及格。一、单项选择题(共50题,每题2分。每题的备选项中,只有一个最符合题意) 1.Text 2Each advance in microscopic technique has provided scientists with new perspectives on the function of living organisms and the nature of matter itself. The invention of the visible-light microscope late
2、 in the sixteenth century introduced a previously unknown realm of single celled plants and animals. In the twentieth century, electron microscope have provided direct views of viruses and minuscule surface structures. Now another type of microscope, one that utilizes X rays rather than light or ele
3、ctrons, offers a different way of examining tiny de tails; it should extend human perception still farther into the natural world.The dream of building an X-ray microscope dates to 1895; its development, however, was virtually halted in the 1940’ s because the development of the electron micro
4、scope was progressing rapidly. During the 1940’ s, electron microscopes routinely achieved resolution better than that possible with a visible-light microscope, while the performance of X-ray microscopes resisted improvement. In recent years, however, interest in X-ray microscopes has revived,
5、 largely because of advances such as the development of new sources of X-ray illumination. As a result, the brightness available today is millions, of times that of X-ray tubes, which, for most of the century, were the only avail able sources of soft X rays.The new X-ray microscopes considerably imp
6、rove on the resolution provided by optical microscopes. They can also be used to map the distribution of certain chemical elements. Some can form pictures in extremely short times; others hold the promise of special capabilities such as three-dimensional imaging. Unlike conventional electron microsc
7、opy, X-ray microscopy enables specimens to be kept in air and in water, which means that biological samples can be studied under conditions similar to their natural state. The illumination used, so-called soft X rays in the wavelength range of twenty to forty angstroms (an angstrom is one ten - bill
8、ionth of a meter), is also sufficiently penetrating to, image intact biological cells in many cases. Because of the wavelength of the X rays used, soft X-ray microscopes will never match the highest resolution possible with electron microscopes. Rather, their special properties will make possible in
9、vestigations that will complement those performed with light-and-electron-based instruments.Why does the author mention the visible-light microscope in the first paragraph()ATo begin a discussion, of sixteenth-century discoveries.BTo put the X-ray microscope in a historical perspective.CTo show how
10、limited its uses are.DTo explain how it functioned.2.Text 2Each advance in microscopic technique has provided scientists with new perspectives on the function of living organisms and the nature of matter itself. The invention of the visible-light microscope late in the sixteenth century introduced a
11、 previously unknown realm of single celled plants and animals. In the twentieth century, electron microscope have provided direct views of viruses and minuscule surface structures. Now another type of microscope, one that utilizes X rays rather than light or electrons, offers a different way of exam
12、ining tiny de tails; it should extend human perception still farther into the natural world.The dream of building an X-ray microscope dates to 1895; its development, however, was virtually halted in the 1940’ s because the development of the electron microscope was progressing rapidly. During
13、the 1940’ s, electron microscopes routinely achieved resolution better than that possible with a visible-light microscope, while the performance of X-ray microscopes resisted improvement. In recent years, however, interest in X-ray microscopes has revived, largely because of advances such as t
14、he development of new sources of X-ray illumination. As a result, the brightness available today is millions, of times that of X-ray tubes, which, for most of the century, were the only avail able sources of soft X rays.The new X-ray microscopes considerably improve on the resolution provided by opt
15、ical microscopes. They can also be used to map the distribution of certain chemical elements. Some can form pictures in extremely short times; others hold the promise of special capabilities such as three-dimensional imaging. Unlike conventional electron microscopy, X-ray microscopy enables specimen
16、s to be kept in air and in water, which means that biological samples can be studied under conditions similar to their natural state. The illumination used, so-called soft X rays in the wavelength range of twenty to forty angstroms (an angstrom is one ten - billionth of a meter), is also sufficientl
17、y penetrating to, image intact biological cells in many cases. Because of the wavelength of the X rays used, soft X-ray microscopes will never match the highest resolution possible with electron microscopes. Rather, their special properties will make possible investigations that will complement thos
18、e performed with light-and-electron-based instruments.According to the passage, the invention of the visible - light microscope allowed scientists to ()Asee viruses directlyBdevelop the electron microscope later onCunderstand more about the distribution of the chemical elementsDdiscover single-celle
19、d plants anal animals they had never seen before3.Text 2Each advance in microscopic technique has provided scientists with new perspectives on the function of living organisms and the nature of matter itself. The invention of the visible-light microscope late in the sixteenth century introduced a pr
20、eviously unknown realm of single celled plants and animals. In the twentieth century, electron microscope have provided direct views of viruses and minuscule surface structures. Now another type of microscope, one that utilizes X rays rather than light or electrons, offers a different way of examini
21、ng tiny de tails; it should extend human perception still farther into the natural world.The dream of building an X-ray microscope dates to 1895; its development, however, was virtually halted in the 1940’ s because the development of the electron microscope was progressing rapidly. During the
22、 1940’ s, electron microscopes routinely achieved resolution better than that possible with a visible-light microscope, while the performance of X-ray microscopes resisted improvement. In recent years, however, interest in X-ray microscopes has revived, largely because of advances such as the
23、development of new sources of X-ray illumination. As a result, the brightness available today is millions, of times that of X-ray tubes, which, for most of the century, were the only avail able sources of soft X rays.The new X-ray microscopes considerably improve on the resolution provided by optica
24、l microscopes. They can also be used to map the distribution of certain chemical elements. Some can form pictures in extremely short times; others hold the promise of special capabilities such as three-dimensional imaging. Unlike conventional electron microscopy, X-ray microscopy enables specimens t
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