问题补充：
— Could you tell me ?
— About half an hour.
A. how long it takes to walk to the Science and Technology Museum from school
B. how long it took to walk to the Science and Technology Museum from school
C. how far was it to walk to the Science and Technology Museum from school
D. how far it was to walk to the Science and Technology Museum from school
答案：
(答案→)A. how long it takes to walk to the Science and Technology Museum from school
B. how long it took to walk to the Science and Technology Museum from school
C. how far was it to walk to the Science and Technology Museum from school
D. how far it was to walk to the Science and Technology Museum from school
解析：考查间接引语。根据About half an hour.可知对时间段回答排除C和D。
根据时态，排除B.
