Tracy said the work would be done by July, ______personally I doubt very much.
【正确答案】 D
【答案解析】本题考查定语从句。分析句子结构可知，逗号后应是一个which引导的非限制性定语从句，which既指代前面整个句子，同时又作后面句子中doubt的宾语，故答案为D)。