Don’t enter the office unless _______.
Tom ________ nothing except how he could manage to earn more money while spending less.
Both countries are looking for ways to __________ their problems in order to build a more peaceful environment.
In my opinion, the best way to deal with a guy who often makes fun of you is to __________ him.
Among all the means of transportation, trains are __________, cheap and the best for long-distance journeys.
Instead of using it at war, scientists are turning to research into the use of nuclear power for__________ purposes.