-- They are quiet, aren't they?

  -- Yes. They are accustomed ______ at meals.

   A. not to talk             B. to not talk     

   C. not to talking          D. to not talking

【解析】：答案D，易误选C。本题考查短语 be accustomed to + n./v-ing，其否定式为 be accustomed to not doing。注意，本题不同于动词不定式 to do 的否定式为 not to do。类似的短语还有 be/get used to (not) doing, pay attention to (not) doing 等含有介词to的短语。