--How does Jack usually go to school?--Heride a bike but now hethere to lose weight.A. us

问题补充：

--How does Jack usually go to school?

--Heride a bike, but now hethere to lose weight.

A. used to, is used to walk

B. was used to, is used to walking

C. was used to, is used to walk

D. used to, is used to walking

答案：

A. used to, is used to walk

B. was used to, is used to walking

C. was used to, is used to walk

(答案→)D. used to, is used to walking

解析： 本题的含义是他曾经习惯于骑自行车，但是现在他习惯于步行，used to+动词原形，表示曾今的含义，be used to doing表示目前习惯于做某事，故本题选D。