Englishfor English speakers
introductory
—
adjective
serving to open or begin
began the slide show with some introductory remarks
—
adjective
serving as an introduction or preface
—
adjective
(= basic)
serving as a base or starting point
a basic course in Russian
basic training for raw recruits
a set of basic tools
an introductory art course
investigation
Noun
—
An investigation is a careful look at a crime, problem, etc. to find the truth or a solution.
Researchers were conducting further investigations into the connection between smoking and lung disease.
The cause of the fire is currently under investigation.