Some researchers are finding that daydreaming may be important to __________ mental health. Daydreaming, they say, is __________ good means of relaxation.

Zhu Zhiwen __________ from a poor countryside finally had a chance to show his talent at the Spring Festival Gala.

—Hi, Tracy, you look tired.
—I'm tired. I __________ the living room all day.

It is desirable that atomic energy should be used for __________ purpose.

In front of me __________, where many athletes from all over the world will compete for Olympic gold medals.