填空题 From that time on, Peter began to work hard and finally got very high grade.
Peter ______ since that time and finally got very high grade.

  • 1、
【正确答案】 1、had worked hard/had been working hard    
【答案解析】[名师解析] 改写的句子中有since that time，说明前面的谓语动词应该使用完成时，而整个句子使用的是过去时，因此，可以考虑使用过去完成时或过去完成进行时。