Mr. White his racing bicycle by himself yesterday, but I am not sure whether it is ready.
A. repaired
B. had repaired
C. was repairing
D. would repair
网友回答
A. repaired
B. had repaired
(答案→)C. was repairing
D. would repair
解析：考查时态。根据后半句可知，“我”还不确定是否已经修好，说明昨天，怀特先生正在修理。故用过去进行时。故选C。