Поставить глагол to introduce во всех временах английского языка.
Simple Progressive Perfect Perfect
Progressive
Present
Past
Future

Present Simple - Introduce/IntroducesPresent Progressive - am/is/are introducing Present Perfect - have/has introducedPresent Perfect Progressive - have/has been introducingPast Simple - introducedPast Progressive - was/were introducing Past Perfect - had introducedPast Perfect Progressive - had been introducingFuture Simple - will introduceFuture Progressive - will be introducing Future Perfect - will have introducedFuture Perfect Progressive - will have been introducing