What song did Cao Ranran compose and sing? Solve it.

He and Ai Yuqiao have a group called Little Daqian. They have many songs, the most classic of which are "If One Day" and "Time flies like water" and so on ... belonging to a folk song group. However, in addition, he also comes from Lei Zi Laughter Factory. He used to be in inflatable dolls and surprise bands, and rock and roll was his favorite. .