1、1Sentences 21 Electric power become the servant of man only after the motor was invented.2 Alloys belong to a half-way house between mixture and compounds.3 No reproduction is granted by implication or otherwise of this information.4 If no value in whole number results, it is rounded up or down acco
2、rding to the figures after the decimal point.5 Stainless steels possess good hardness and high strength.6 In conclusion and convection, energy transfer through a material medium is involved.7 The mechanical energy can be changed back into electrical energy by means of a generator or dynamo.8 Thus th
3、e number of ions builds up very rapidly and a disruptive discharge, or spark, occurs.9 More than 100 chemical elements are known to man; of these, about 80 are metals.10. These elements seem to be working well under high voltage.11. From the moon light takes little more than a second and a quarter i
4、n reaching us, so that we obtain sufficiently early information of the condition of our satellite.12. Farm tractors are big users of diesel power.13. The square on the longest side of any rightangled triangle is equal to the squares on the other sides added together.14. A burglar alarm is a device f
5、or giving warning that thieves are trying to enter a building.15. For generations coal and oil have been regarded as the chief energy sources used to transport men from place to place.16. Semiconductor devices have no filament or heaters and therefore require no heating power or warmed-up time.17. Y
6、ou have to change the gear manually in this car; it is not automatic.18. Many people would rather have gas to knock them out before they have their teeth out.19. It was Newton who proved mathematically that the path of a planet must be an ellipse.20. Butterflies have thin antennae (or “feelers”) wit
7、h tips like little knobs, while months have feathery or threadlike antennae.21. Modern theories of the development of stars suggest that almost every star has some sort of family of planets.22. Acupuncture is the placing of hair-thin needles into the skins at special points of the body to ease pain
8、and treat ailments.23. The eye is actually about the size of a table-tennis ball. Much of it lies within the skull. The front portion of the eye is made up of three parts-the cornea, the iris and the pupil. It is protected by the eyelid and eyelashes.24. The global satellite phone service has opened
9、 for business, giving people the power to make and receive call anywhere from Mount Qomolangma to the Dead Sea.25. Cloning techniques vary from simple plant cuttings to the replication of adult mammals from their genetic material.26. Edison tried a thousand different filaments before he found one th
10、at he could use. 27The intensity of light is directly proportional to the candle power of its source.28. They were one-cylinder or two-cylinder engines, of which some were make-and-break and others jump-spark.29. The several changes which nectar undergoes in becoming honey begin in the honey crop.30
11、. A laser is a device for light amplification by stimulated emission of radiation. 31. A visicorder is provided to record current and voltage waveforms.32. Carbon dioxide does not burn or support combustion. 33. This canal is filled with a liquid, similar in comparison to lymph. 34. Extract is clay
12、treated and rerun with pure benzene as an overhead product. 35Inorganic chemistry is linked closely to geology, mineralogy and metallurgy; organic chemistry to physiology, biochemistry, and biology in general. 35. There have been opened up to the vast and excellent science, in which my work is the b
13、eginning, ways, by which other minds more acute than mine, will explore its remote corner. 36. Knowledge , in any art or science, being always the fruit of observation, study, or practice, gives, in proportion to its extent and usefulness, the possessor a just claim to respect.37Lines of magnetic fo
14、rce never touch or come across each other.38. Thus, it would be correct to say that the distance to the sun, from where we are on the earth, is about 1 million walking days.39. Power can be converted from mechanical form to electrical form and back again to mechanical form with almost 100 percent ef
15、ficiency.40. Ions, produced by dissociation of molecules, drift through the solution when a potential difference is maintained.41. Metal can bear beating with a hammer, which a stone cant.242. We regret to inform you that there is a shortweight of 4.5M/T only. Therefore, we lodge a claim against you
16、 for shortweight of 4.5M/T.43. The ozone layer which surrounds the earth performs an important function: it shields the planet from strong ultraviolet radiation.44. A computer can be made to do all the problems that its human operator could do if he had unlimited time to make his computations. The m
17、achine, however, will let you have the answer much faster.45. Gathering facts, confirming them, suggesting theories, testing them, and organizing findings-this is all the work of science.46. Microwaves, which have a higher frequency than ordinary radio waves, are used routinely in sending thousands
18、of telephone calls and television programs across long distances.47. Another solar electric technology is photovoltaics. It uses silicon or other semiconductors to convert the suns rays directly into electricity.48. Scientists have already known that under the extreme temperatures, say -260C, metal
19、presents zero resistance, that is, superconductivity of metal.49. Office automation applications include word processing, data entry, electronic mail, image processing, voice processing, and office information systems.50. Superior to the existing telephone, the videophone, or laser phone, can transm
20、it voice and image simultaneously along its telephone line which is made of optic-fiber.51. AIDS, Acquired Immune Deficiency Syndrome, is usually a fatal disease which leaves the body unable to ward off infection.52. It is quite possible that failure to eat enough to maintain optimum vitamin levels
21、can cause behavioral and personality changes. These may include insomnia, loss of appetite, and irritability.53. Proteins consist of carbon, hydrogen, oxygen, nitrogen, sulphur and phosphorus. During digestion proteins are broken down to their simplest form, that is, amino acids, and it is as amino
22、acids that they are absorbed.54. Within 30 to 40 years, two-hour commercial flights will link New York and Tokyo, with planes that “see” through fog, snow and dust.55. NASA figures that the earliest anyone could go to Mars is 2012 if sufficient government funding is given, which is unlikely at prese
23、nt.56. A relatively powerful notebook computer, with a 166-Mhz Pentium-class processor, 16 megabytes of RAM, a 2-gigabyte hard drive, a CD-ROM drive, and a 12-inch screen, is now about US $ 1,600. 57. Television is the transmission and reception of images of moving objects by radio waves.58The direc
24、tion of motion can be changed by the action of another force on a body.59. The propagation of such microwaves will be explained in terms of equations.60This tendency of charged objects to become neutralized results in a certain force which acts on the electrons by either attracting them towards or r
25、epelling them away from the charged objects.61The velocity of gas passing over the object to be cooled determines the rate of heart transferred to the objects.62The automatic production line is found in proper operation.63Since numerical control was adopted at machine tools, the productivity has bee
26、n raised greatly.64It is a space rock captured and now held in orbit by the gravity force of Mars.65After some underground nuclear tests, large numbers of tiny aftershocks are recorded during the next few weeks.66. In place of these fuels, more sun and wind power should be used to provide electricit
27、y, heat and transportation.67. The mechanical energy can be changed back into electrical energy by a generator.68The results obtained suggest that most isotopes produced artificially are radioactive.69. Calories are known to be a measure of the heat energy of food given to the body.70Weak magnetic f
28、ields are known to come from the human body.71The theoretical prediction was compared to the results from the simulated tests and was found to be applicable to power system.72. What particularly interested Stephen was singularities, strange beasts predicted by general relativity.73. The 1960s saw the great advance in electronics industry with the emergence of the large-scale integrated circuits.74. Animals that hibernate practice energy conservation to a greater extent than those that do not. 75. The very number of the constituent particles makes their motion appear to be somewhat random.
