专四专八考试

【单选题】Decide which of the choices given below would best complete the passage if inserted in the corresponding blanks. Mark the best choice for each blank on your answer sheet.
Cells cannot remain alive outside certain limits of temperature, and much narrower limits mark the boundaries of effective functioning.Enzyme systems of mammals and birds are most efficient only within a narrow (31) around 37℃; a(32) ,of a few degrees from this value seriously impairs their functioning.Even though cells can survive wider (33) , the integrated actions of bodily systems are impaireD、Other animals have a wider tolerance (34) changes of bodily temperature.
For centuries (35) has been recognized that mammals and birds differ from other animals in the way they regulate body temperature. Ways of (36) the difference have become more accurate and meaningful over time, but popular terminology still reflects the old division (37) "warm blooded" and "cold blooded" species; warm blooded included mammals and birds, (38) all other creatures were considered cold bloodeD、 (39) more species were studied, it became evident that this classification was (40) .A、fence lizard usually has a body temperature only a degree or two below (41) of humans and so is not colD、 (42) the next distinction was made between animals that maintain a (43) body temperature and those whose body temperature varies with their environment.But this classification also proved inadequate, (44) among mammals there are many that vary their body temperatures during hibernation. (45) , many invertebrates that live in the (46) of the ocean never experience a change in the chill of the deep water, and their body temperatures remain constant. The current distinction is between animals whose body temperature is (47) chiefly by internal metabolic processes and those whose temperature is regulated by the (48) . The latter do so mainly by moving to favorable sites or by changing their exposure to (49) sources of heat. Mammals and birds also regulate their temperature by choosing favorable environments, but primarily they regulate their temperature by malting a variety of internal (50)
A、change B、gap
C、fluctuationD、increase
网考网参考答案：C
网考网解析：
[解析] 上文说明了温度有变化，细胞功能就会受到影响。本句提到尽管细胞可以承受较大的温度变化，但生物机体的综合功能会受到影响。因此答案可在change和fluctuation当中进行选择。结合前面的修饰语wider．可知答案应为fluctuation。 [点睛] 语义关联题。change作名词经常与big, dramatic等词搭配。但不能用wide修饰。 document.getElementById("warp").style.display="none"; document.getElementById("content").style.display="block"; 查看试题解析出处>>