I'm going to work, see you later.

He is always joking around during class.

The underground water in this area is very clean and is used as drinking water.

Mr. Aman is my best friend.

Makoto is my best friend.

This park is open to everybody.

The flags of all nations are fluttering in the wind.

Just in case he fails the exam, what should we do?

He is knowledgeable in all fields of learning.

Jus gentium is a universal law that applies to all people.