【正文】 資源共享 ) 第 1 頁 共 40 頁 1996 年 8 月托福閱讀全真試題 Questions 110 The word laser was coined as an acronym for Light Amplification by the Stimulated Emission of Radiation. Ordinary light, from the Sun or a light bulb, is emitted spontaneously, when atoms or molecules get rid of excess energy by themselves, without any outside intervention. Stimulated emission is different BECause it occurs when an atom or molecule holding onto excess energy has been stimulated to emit it as light. Albert Einstein was the first to suggest the existence of stimulated emission in a paper published in 1917. However , for many years physicists thought that atoms and molecules always were much more likely to emit light spontaneously and that stimulated emission thus always would be much weaker. It was not until after the Second World War that physicists began trying to make stimulated emission dominate. They sought 中國最大的管理資源中心 (大量免費資源共享 ) 第 2 頁 共 40 頁 ways by which one atom or molecule could stimulate many other to emit light , amplifying it to much higher powers. The first to succeed was Charles , then at Colombia University in New York . Instead of working with light , however, he worked with microwaves, which have a much longer wavelength, and built a device he called a maser for Microwave Amplification by the Stimulated Emission of Radiation. Although he thought of the key idea in 1951, the first maser was not pleted until a couple of years later. Before long, many other physicists were building masers and trying to discover how to produce stimulated emission at even shorter wavelength. The key concepts emerged about 1957. Townes and Arthur Schawlow, then at Bell Telephone Laboratories, wrote a long paper outlining the conditions needed to amplify stimulated emission of visible light waves. At about the same time, similar ideas crystallized in the mind of Gordon Gould, then a 中國最大的管理資源中心 (大量免費資源共享 ) 第 3 頁 共 40 頁 37 yearold graduate student at Columbia, who wrote them down in a series of notebooks. Townes and Schawlow published their ideas in a scientific journal, Physical Review Letter, but Gould filed a patent application. Three decades later,people still argue about who deserves the credit for the concept of the laser. word coined in line 1 could best be replaced by (A) created (B) mentioned (C) understood (D) discovered word intervention in line 5 can best be replaced by (A) need 中國最大的管理資源中心 (大量免費資源共享 ) 第 4 頁 共 40 頁 (B) device (C) influence (D) source word it in line 6 refers to (A) light bulb (B) energy (C) molecule (D) atom of the following statements best describes a laser? (A) A device for stimulating atoms and molecules to emit light. (B) An atom in a highenergy state. (C) A technique for destroying atoms or molecules. (D) An instrument for measuring light waves. 中國最大的管理資源中心 (大量免費資源共享 ) 第 5 頁 共 40 頁 was Towne39。s early work with stimulated emission done with microwaves? (A) He was not concerned with light amplification. (B) It was easier to work with longer wavelengths. (C) His partner Schawlow had already begun work on the laser. (D) The laser had already been developed. his research at Columbia University, Charles Townes worked with all of the following EXCEPT (A) stimulated emission (B) microwaves (C) light amplification (D) a maser approximately what year was the first maser built? 中國最大的管理資源中心 (大量免費資源共享 ) 第 6 頁 共 40 頁 (A) 1917 (B) 1951 (C) 1953 (D) 1957 word emerged in line 28 is closest in meaning to (A) increased (B) concluded (C) succeeded (D) appeared word outlining in line 30 is closest in meaning to 中國最大的管理資源中心 (大量免費資源共享 ) 第 7 頁 共 40 頁 (A) assigning (B) studying (C) checking (D) summarizing do people still argue about who deserves the credit for the concept of the laser? (A) The researchers39。s hand applied every stroke of the brush. More likely, numerous assistants, who had been trained to imitate the artist39。s shop probably provided the frame and perhaps supplied the panel, and yet another shop supplied the gold. Thus, not only many hands , but also many shops were involved in the final product. In spite of problems with their condition, restoration, and preservation many panel paintings have survived, and today many of them are housed in museum collections. aspect of panel paintings does the passage mainly discuss? 中國最大的管理資源中心 (大量免費資源共享 ) 第 11 頁 共