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

Present Simple - Introduce/Introduces
Present Progressive - am/is/are introducing 
Present Perfect - have/has introduced
Present Perfect Progressive - have/has been introducing
Past Simple - introduced
Past Progressive - was/were introducing 
Past Perfect - had introduced
Past Perfect Progressive - had been introducing
Future Simple - will introduce
Future Progressive - will be introducing 
Future Perfect - will have introduced
Future Perfect Progressive - will have been introducing