The origin of the fire is unknown. ✬

What is the origin of the universe? ✬

The origin of the universe will probably never be explained. ✬

This word is also French in origin. ✬

Let me tell you about the origin of this school. ✬

I don't know the origin of the rumor. ✬

There are many theories about the origin of life. ✬

That word is of Greek origin. ✬

Its origin is unclear. ✬

Its origin remains unknown. ✬