单项选择题
|  What can be said of the normal process 
of aging, from a linguistic point of view In general (1) , 
there is a clear and (2) relationship: no-one would have much 
difficulty (3) a baby, a young child, a teenager, a 
middle-aged person, or a very old person from a tape recording. With 
children, (4) is possible for specialists in language 
development, and people experienced (5) child care, to make 
very detailed (6)  about how language correlates with age in 
the early years. (7) is known about the patterns of 
linguistic change that affect older people. It is plain that our voice quality, 
vocabulary, and style alter (8) we grow older, but research 
(9) the nature of these changes is in its earliest stages. However. 
a certain amount of (10) is available about the production 
and (11) of spoken language by very old people, especially 
regarding the phonetic changes that take place. Speech is (12) to be affected by reductions in the (13) of the vocal organs. The muscles of the chest (14) , the lungs become less elastic, the ribs (15) mobile: as a result, respiratory efficiency at age 75 is only about half (16) at age 30, and this has (17) for the ability to speak loudly, rhythmically, and with good tone In addition, speech is affected by poorer movement of the soft palate and changes in the facial skeleton, especially around the mouth and jaw. There are other, more general signs of age. Speech rate slows, and fluency may be more erratic. Hearing (18) , especially after the early fifties. Weakening (19) of memory and attention may affect the ability to comprehend complex speech patterns. But it is (20) all had news: vocabulary awareness may continue to grow, as may stylistic ability—skills in narration, for example. And grammatical ability seems to be little affected.  |