Research shows that humans ______ from selfish to unselfish behavior when they are watched.
Not many of us really get to see the hard work that happens ______ the scenes to make our favorite movies come to life.
I dreamed of some animals running on the moon.— It ____ be. There is no air or water on the moon, you know.
You seem tired, David.—YesI _____ all day long and can’t wait to go to bed now
Weshould consider the students’ request _____the school libraryprovide more books on popular science.