He is interested in the history of the Old World.

This world line connects time and space.

Please teach me how to find the greatest common divisor.

He likes to take a walk in the park at dusk.

As the saying goes, 'spare the rod and spoil the child', if you pamper them, children will not grow.

She is conducting research on the world's oldest profession.

Old World monkeys primarily inhabit Africa and Asia.

The World Trade Organization is an important organization that sets the rules for international trade.

The World Health Organization is working to improve public health worldwide.

New World monkeys live in South America.