have you repaired your bike ,bob 教教题啦

--Have you repaired your bike,Bob?
--Yes,I (repaired) it twenty minutes ago.
鲍勃,你已经修好单车了?是的,我二十分钟前修好.
问句是现在完成时态,但答句的时间状语是……ago(多久以前),应该为一般过去时态.