To make an extensive investigation into.
To search or examine with continued care; to seek diligently.
To search again.
Diligent inquiry or examination to seek or revise facts, principles, theories, applications, etc.; laborious or continued search after truth.
The research station that houses Wang and his team is outside Lijiang, a city of about 1.2 million people. File:The research station that houses Wang and his team is outside Lijiang.ogg
To examine something with great care or detail, as to look for hidden or obscure flaws.
To audit accounts etc in order to verify them.