单项选择题
Although vocal cords are lacking in cetaceans,
phonation is undoubtedly centered in the larynx.
The toothed whales or odontocetes (sperm whale
Line and porpoises) are much more vociferous than the
(5) whalebone whales, or mysticetes. In this country
observers have recorded only occasional sounds
from two species of mystieetes (the humpback and
right whale). A Russian cetologist reports hearing
sounds from at least five species of whalebone
(10) 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
(15) brain are much more highly developed in the odon-
tocetes than in the mysticetes, in fact, to a degree
unsurpassed by any other mammalian group.
A．animals with more highly developed auditory apparatuses tend to produce more sounds
B．animals without vocal cords tend to produce as much sound as those with vocal cords
C．highly intelligent animals tend to produce more sound than less intelligent species
D．the absence of vocal cords has hindered the adaptation of cetaceans
E．sound is an important means of communication among whales