blindness above all other disabilities.Yet deafness can be an even more severe handicap(缺陷)，especially in early life，when children learn language.This is why Helen Keller's achievements were so extraordinary.

　　As a result of an illness at the age of 19 months，she lost both sight and hearing and sank into a totally dark，silent world.She was rescued from this terrible separation by her teacher，Anne Sullivan，who managed to explain，by tapping signs into the little girl's palm，that things have names，that letters make up words，and that these can be used to express wants or ideas.

　　Helen Keller later grew into a writer and a well­known advocate for the handicapped.Her remarkable development owed a great deal to her determination，her teacher，and her family.But it also showed that when a sense (or two，in Helen Keller's case) is missing，another sense (in her case，touch) may be trained to make up for the loss，at least in part.

　　Our nervous system reacts only to a selected range of wavelengths，vibrations，or other properties.It is limited by our genes，as well as our previous experience and our present state of attention.

　　What draws our attention，in many cases，is change.Our senses are finely adjusted to change.Stationary or unchanging objects become part of the scenery and are mostly unseen.Usual sounds become background noise，mostly unheard.The feel of a sweater against our skin is soon unnoticed.

　　【语篇解读】　我们通过感觉器官来了解世界上的事物，一般来说，人们有五种感觉器官，每一种都很重要且几乎是不可以替代的。不过在某种程度上听觉有点比其他感官重要些。

　　1．The author refers to Helen Keller in order to ．

　　A．prove deafness is more severe handicap than others

　　B．encourage deaf people to learn from her

　　C．show it is important to learn language in early life

　　D．suggest hearing is precious and irreplaceable

A　[推理判断题。根据第二段倒数第二句话可知，听觉在某种程度上比其