单选题 {{B}}Directions:{{/B}} There are 5 reading passages in this part. Each passage
is followed by some questions or unfinished statements. For each of them there
are four choices marked A, B, C, and D. You should decide on the best choice and
mark your answer on the ANSWER SHEET by blackening the corresponding letter in
the brackets.
Although vocal cords are lacking in
cetaceans, phonation is undoubtedly centered in the larynx. The
toothed whales or odontocetes (sperm whales and porpoises) are much more
vociferous than the whalebone whales, or mysticetes. In this country observers
have recorded only occasional sounds from two species of mysticetes (the
humpback and right whale). A Russian cetologist reports hearing sounds from at
least five species of whalebone whales but gives no details of the circumstances
or descriptions of the sounds themselves. Although comparison of the
sound-producing apparatus in the two whale groups cannot yet be made, it is
interesting to note that the auditory centers of the brain are much more highly
developed in the odontocetes than in the mysticetes, in fact, to a degree
unsurpassed by any other mammalian group.
单选题
Which of the following animals has the most highly developed auditory center in the brain?
【正确答案】
D
【答案解析】巨头鲸的大脑具有非常发达的听觉中枢。答案的依据是：…it is interesting to note that the auditory centers of the brain are much more highly developed in the odontocetes than in the mystieetes…。在这个句子中，术语odontocetes指sperm whales(巨头鲸)。