This research paper directly refers to the original text.

The study of the atomic nucleus is an important field in physics.

It's difficult to understand this text.

What does this wording mean?

He was immersed in a world of fantasy.

I was surprised by his sudden appearance.

Suddenly, he appeared in the room.

Database transactions need to ensure their atomicity.

The price of crude oil is rising.

Nouns form the main part of the sentence.