(1) The Montreal International Exposition,“Expo. 67”was applauded for displaying an degree of taste superior to that of similar expositions.
(答案) B 改为a degree。
(2) If a atom loses any of its electrons, it becomes positively charged and can combine chemically with other atoms.
(答案) A改为an atom
(3) Since the beginning of this century the United States government has played an role in the supervision and use of the nation’s natural resources.
(答案) A改为a role
(4) A electric current can consist of charges that are positive, negative, or both.
(答案) A 改为An election
2. 可数名词前面通常要有冠词或其它限定形容词, 非泛指的可数名词一般不能独立存在。
(1) A march is highly rhythmic piece of music first used by military bands to accompany marching. (94.1)
(答案) A 名词短语 piece of music 前面应加不定冠词：a highly rhythmic piece of music
(2) The sonometer is instrument used to study the mathematical relations of harmonic tones. (93.8)
(答案) A改为an instrument, instrument为可数名词，前面应有冠词。
(3) Accounting is described as art of classifying, recording, and reporting significant financial events.
(答案) A 名词art,表示“一门艺术”这个概念时，应加冠词。此句应改为an art。
(1) The Yukon River, which fllows into the Baring Sea, gives its name to a region of Alaska and a territory of the Canada.
(答案) D删掉定冠词the. Canada是专有名词，无需加冠词。表示“国家”“城市”“人物”等概念的专有名词前不加冠词。
(2) Langston Hughes, a prolific writer of the 1920’s was concerned with the depicting the experience of urban Black people in the United States.
(答案) C 删除冠词the。动名词前不应加冠词。特别是当这个动名词带有宾语，它的动词属性更强烈，因而不能加冠词。
(3) Some geologists predict that, by end of the next century, movement along the San Andreas Fault will have caused part of California to separate from the continent (88.1)
(答案) A 加入定冠词the,组成固定短语by the end。含冠词的词组不能随意删除或更换。
(4) At a first, the scientific method may appear to be a narrow and restrictive way of gaining (89.10)
(答案) A 删除不定冠词a。At first为固定短语结构，不能随意添入冠词。
(5) Seven of planets rotate in the same direction as their orbital motions, while Venus and Uranus rotate in the opposite direction. (91.8)
(答案) A 此句的planets特指太阳系中的九大行星，故应加入定冠词the,即Seven of the planets……。