I completed this subject paper with diligent research and study.

经过我的刻苦钻研和学习，我已经把这个课题做完了。

youdao

His diligent research of our Earth and solar system led to groundbreaking discoveries that, at the time, were extremely controversial.

他对于地球和太阳系的辛勤研究带来了突破性的发现，而这种发现在当时极具争议性。

youdao

Professor Huggins was diligent enough to obtain a diploma in space research.

哈金斯教授很勤奋，他获得了太空研究方面的一个文凭。

youdao

It is only through diligent research that risk and harm can be determined, quantified and, when necessary, regulated to reflect the public interest.

FORBES: Using Science As the Guiding Hand of Food Policy

Along with a growing sense of well-being, I did come across many interesting facts about the hap biz that diligent research has unearthed.

FORBES: Magazine Article

As the CEO of a new-age market research company, I was thrilled to see that their first recommendation was diligent market research.

FORBES: How To Save Your New Business Idea with Market Research