Each 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 previously unknown realm of single-celled
plants and animals. In the twentieth century, electron microscopes have
provided direct views of viruses and minuscule surface structures. Now
another type of microscope, one that utilize x-rays rather than light or
electrons, offers a different way of examining tiny details, 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 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 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 available sources of soft x-rays. The new x-ray microscopes considerably improve 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 microscopy,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 fort angstroms (an angstrom is one ten-billionth 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 investigations that will complement those performed with light- and electron-based instruments.
1 -5 Answer the question below based on the text above
1. What does the passage mainly discuss?
a. A new kind of microscopic
b. Sources of illumination for microscopes
c. Outdated microscopic technique
d. The detail seen through microscope
2. According to the passage, the invention of the visible-light microscope allowed scientist to
a. Discover single celled plants and animals they had never seen before
b. Understand more about the distribution of the chemical elements
c. Develop the electron microscope later on
d. See viruses directly
3. Why did it take so long to develop the x-ray microscope?
a. The source of illumination was not bright enough until recently
b. X-ray microscope were too complicated to operate
c. Material used to manufacture x-ray tubes were difficult to obtain
d. Fund for research were insufficient
4. Based on the information in the passage, what can be inferred about x-ray microscopes in the future?
a. They will probably replace electron microscopes altogether
b. They will provide information not available from other kinds of microscopes
c. They will eventually be much cheaper to produce than they are now
d. They will eventually change the illumination range that they now use
5. The word “minuscule” in the passage is closest in meaning to
a. Circular c. Dangerous
b. Complex d. Tiny
6. A ________ of thieves is in the jewelry shop
a. group c. gang
b. trio d. school
7. I saw a _______ of kangaroos hopping across the road
a. pack c. swarm
b. herd d. troop
8. A herd of buffaloes ___ eating on the field
a. are c. is
b. will d. shall
9. A parliament of owls _____ roasting in the rafter
a. are c. was
b. is d. were
10. “I’m sure to win the discus again this year,” Abdul _______
a. ducked c. chicken out
b. aped d. crowed
11. Sony ______ three hamburgers
a. wolfed down c. ducked
b. aped d. crowed
12.Ricko was delighted with his news prosthetic legs ________ he could now fulfill his dream of completing a marathon
a. but c. or
b. and d. yet
13.You can have a new computer ________ you can continue to use your outdated model
a. still c. and
b. or d. but
14.Andre woke up _______ with fear of what the day would bring
a. after all those years c. every morning
b. because of a bad accident d. as soon as possible
15. _________ Bob had lived without the use of arms
a. With joy in his heart c. Every night
b. All his life d. In a few minutes
16. When Sarah won the first prize in the competition, everyone felt ________ for her
a. friendly c. ashamed
b. sad d. happy
17. We ______ Andi because although he sings so well, he is also humble
a. dislike c. pity
b. admire d. dread
18. I have lived in Malaysia _______ almost ten years
a. for c. before
b. after d. during
19. I play football in the park ______ evening at seven
a. in c. every
b. twice d. since
20. I felt very ______ as I waited for her at the school gates
a. nervous c. famous
b. surprised d. angrily
21. _____ dinosaurs lived on earth before man appeared
a. all the c. all
b. every d. each
22. “_____ exhibit in the Dinosaur Museum is very interesting,” said the teacher
a. every c. all the
b. all d. each
23. _______ fossils in this area are those of herbivorous dinosaurs
a. all the c. all
b. every d. each
24. On the dinosaur hunt, we _______ clues
a. listened c. touched
b. looked for d. tasted
25. We gathered all the _______ we could find and took it back to the laboratory
a. ideas c. evidence
b. stories d. people
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