research vs vehicle inspection

research

noun
  • 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 

verb
  • To search or examine with continued care; to seek diligently. 

  • To make an extensive investigation into. 

  • To search again. 

vehicle inspection

noun
  • A procedure mandated by national or subnational governments in many countries, in which a vehicle is inspected to ensure that it conforms to regulations governing safety, emissions, or both. Inspection can be required at various times, e.g., periodically or on transfer of title to a vehicle. 

How often have the words research and vehicle inspection occurred in a corpus of books? (source: Google Ngram Viewer )