researched

这3者意思稍有不同:research in着重指对…学科的研究; research into指更深入地研究以弄个水落石出; research on着重指对特定问题的研究。

这两个词都有“调查”的意思。它们的区别在于:examination指对人或物仔细查验以获得实际情况,而research则指对实际情况或第一手资料的研究或调查以揭示新的知识。例如:

You may conduct your research for the term paper in the library.你可以在图书馆里为写学期论文进行研究工作。

It will be found upon examination that someone must have made a mistake.一经调查,便会发现有人犯了错误。

They're researching in medieval history.

They're researching into medieval history.

They're researching on medieval history.

他们正在研究中世纪历史。