We six days a week, but now we only work five days.
A. used work
B. are used to work
C. used to working
D. used to work
网友回答
A. used work
B. are used to work
C. used to working
(答案→)D. used to work
解析：句意：我们过去常常一周工作六天，但是我们现在只工作五天了。Used to do sth过去常常做某事。To是不定式符号，后面接动词原形。be used to sth习惯于某事，故选D。