A-A+ He has been working hard at his() (博士的) thesis 2022-08-12 22:27:01 问答库 阅读 198 次 问题详情 He has been working hard at his() (博士的) thesis on computer for more than half a year.A、master ’sB、bachelor ’sC、doctoralD、professional 参考答案 参考答案：C
