do you study for a test— I study by working with my classmates.

I can’t find my pen. Could you help____________ findit

－Why don’t your parents buy the house now They are rich enough.－They are waiting for a _______ price.

Water is vital _______every living thing ______, without which the world would be a dead place.[ ]

Look! The man at the gate ____ be our headmaster. He is always standing there every morning.– No, it _____ be him. He is holding a meeting in the office now.