It’s difficult to use ______ unless you understand the technology behind them.
_______ has been a topic of continual geological research.
The phrase "keeps sellers on their toes" in the passage mostly means "______".
We must push the piano to the corner of the hall to_____________________ our party tonight.
The examination was not very difficult, but it was_____________________ long.
Standing on the tip of the cape,____________________ .
As a millionaire who liked to show off her wealth, Mrs. Smith paid______________________________________________ we asked.
He_______________us but he was short of money at the time.
The word "allocated" in the passage mostly means "______".
The packages___________________ so that it would be easier to carry them.
______ one of the most beautiful forms of performance art, ballet is a combination of dance and mime performed to music.