往下拉阅读中文版。 Have you ever seen a picture of the Great Pyramid of Egypt? It’s one of the most mysterious and incredible buildings in the world — and it's thousands of years old! But here’s the strange part: No one knows for sure who built it, how they built it, or even why they built it. It’s made of over 2.3 million giant stones, and some of them were brought from hundreds of miles away! It was the tallest man-made building on Earth for thousands of years. So… what was it reall