---They are quiet，aren’t they?
---Yes. They are accustomed at meals.
A. to talk
B. to not talk
C. to talking
D. to not talking
网友回答
A. to talk
B. to not talk
C. to talking
(答案→)D. to not talking
解析：考查固定词组和动名词的否定式。固定词组be accustomed to sth/doing sth习惯某事/做某事；本词组中的to是介词，后面接名词或者动名词的形式。句意：—他们很安静，不是吗？—是的。他们已经习惯于吃饭的时候不说话了。根据句意本句的动名词形式要使用否定式，就是在动名词前面直接加上not。故D正确。