He has devoted most of his time and energy _______ a cure for the disease.
You must _____ a wide vocabulary if you want to learn a language well.
People often _____ me with my twin sister as we are so alike.
I wanted to catch _____ early train, but couldn’t get _____ ride to the station.
With everything needed_____, Mrs. Jackson went to the supermarket after work in a hurry.
He became self-satisfied because of his _____.