He noticed that someone was behind him.

We go to the playhouse to watch a play on the weekend.

My favorite snack is sesame salt.

He is known as an arm-twister in the company.

My grandfather taught me the technique of catching gobies.

He used the technique of goby catching in the river.

This orrery accurately reproduces the movements of the planets in the solar system.

Ilex aquifolium trees are often used for Christmas decorations.

He tried to solve the problem radically.

A comprehensive reform is necessary to eradicate the root of the problem.