问题补充：
He asked me how much on the mountain bike.
A. did I pay
B. I had spent
C. did I spend
D. I had cost
答案：
A. did I pay
(答案→)B. I had spent
C. did I spend
D. I had cost
解析：通过分析句子，可知这个句子中含有一个宾语从句，宾语从句要用陈述语序，故排除A和C，spend… on sth.是固定用法，意思为在某事上花（金钱或时间等）。
