My homework is not finished yet.

Hydrogen is the most abundant element in the universe.

This plan was perfectly successful.

This project has been completed in its entirety.

She loves murder mysteries and plays them with her friends almost every week.

Madagascar is a country rich in nature.

His explanation was impossible to understand.

This is part of my collection, especially the Arabian cowry is rare.

Rare earth elements are essential materials for the manufacture of electronic devices.

An isotope refers to elements with the same atomic number but different numbers of neutrons.