问题补充：
He go out with his parents, but now he staying at home alone.
A. used to; is used to
B. is used to; used to
C. use to；is used to
D. used to; used to
答案：
(答案→)A. used to; is used to
B. is used to; used to
C. use to；is used to
D. used to; used to
解析：be used to sth习惯于某事;used to do sth过去常常做某事. sth be used to do sth某物被用来做某事。句意：他过去常常和他的父母一起出去，但是现在他习惯了独自呆在家里面。结合语境可知选A。
