问题补充:
---- you a bus to school?
---- Yes. But now I usually go to school on foot.
A. Do, like to take
B. Do, take
C. Did, used to take
D. Are, used to taking
答案:
A. Do, like to take
B. Do, take
(答案→)C. Did, used to take
D. Are, used to taking
解析:根据“But now I usually go to school on foot.”句意,应指过去。故选C。used to do指“过去常常做某事”