问题
How do you often go to school——I _____take a bus ，but now I _____walking.
A:used to ， use to
B:was used to， am used to
C:am used to， used to
D:used to， am used to;
B:was used to， am used to
C:am used to， used to
D:used to， am used to;
正确答案是：
