Planet Earth

How long can a whale stay under water?

World

Which is the highest denominated US dollar note?

Planet Earth

What is the Earth made of? What is beneath its crust?

World

Did any of the US presidents own slaves?

World

What is the origin and history of the dollar sign?

Outer Space

How did our Milky Way Galaxy originate? What led to the formation of such a huge entity?

World

Which is the world’s oldest city still inhabited as in the past?

World

What does the inside of Eskimos’ igloo look like?

Human Biology

Why do we feel thirsty after consuming salt?

Science and Technology

How to find the right direction without a compass?

Planet Earth

How was it proven that the Earth is round and not flat?

How things work

Who invented stethoscope? How does it work?

How things work

How is colorful striped toothpaste manufactured?

Science and Technology

Who Invented The Word Cyberspace? What Does It Mean?

Science and Technology

Why is the pointing device used for computers called a mouse? Who invented it?