She devoted herself ________to her research and it earned her a good reputation in her field.

The happiest of people don’t ______ have the best of everything; they just make the most of everything that comes along their way.

The boys are doing no harm; they are ___ playing．

It rained that day and ________ the basketball game was called off.

—Credit cards are       useful when traveling.—True. They save us the trouble of taking too much cash.