Please check before you throw away the eggshell.

What is this mixture made of?

The traffic light turned red, so I stopped.

His opinion is always rational.

He is serving as the president's guard.

He drew a pentagon on the blackboard.

Metalinguistics is an important concept in linguistics.

In this project, it is necessary to combine various data.

It's difficult to remember new words.

His native language is Spanish.