Which letter is very useful to a deaf man?

Which letter is very useful to a deaf man? 1.which letter is very useful to a deaf woman? Which letter is very useful to a deaf woman? Which letter is very useful to a deaf woman?哪个字母对一个盲人而言很重要? Which letter is useful to a deaf woman? Which letter is most useful to a deaf woman? 几道英语智力题1.Which letter is very useful to a deaf woman 2.I hav 两道英文智力测试题~1.which letter is very useful to a deaf woman?2.th which letter is the most useful to a man 帮解决两道奥英智力题1:Which letter is the most useful to a deaf girl? 英语问题提问急这些是智力题．．急．．1．which letter is very useful to a deaf wo which letter is very important to a bilnd man?