( )1. It’s your job________ the pop stars.
A. introduce B. introduci ng C. introduces D. to introduce
( )2. They’d like ____ thank the people _____their help and support.
A. to; to B. for; for C. to; for D. for; to
( ) 3. —Have you finished the work?
—Not yet, but we'll keep ________ until we make it.
A. failed B. trying C. tried D. failing
