When I passed the river, I saw some children ______ on the sand.
The children stood in ______ circle and danced to music.
—The meeting will begin at 3 p.m. ________ be late. —All right.
—Are they ________ animals? —Yes, there are few of them in the world now. We should protect them.
—Why do you like that band? —Because they play ________ their own songs.
—What’s electricity? —It’s a form of energy _______ we use in our daily lives.