【题目】—They like going to sleep early，don't they?
—Yes.They are accustomed ________ very late.
A.to stay up
B.to not stay up
C.to staying up
D.to not staying up

【答案】D
【解析】be accustomed to sth./doing sth.意思为“习惯于……”，to为介词，后接动名词；动词不定式的否定在to前加not，而介词to表否定意义，应在后面的动名词前加not；句意：—他们喜欢较早睡觉，是吗？—是的。他们习惯了不熬夜过晚。根据句意，故选D。