The Great Pyramid of Giza is one of the Wonders of the Ancient World. It was b    21    more than 4, 000 years ago in Egypt. It is so p    22    that millions of tourists from around the world come to visit it every year.

In Egypt there are over 80 pyramids and the l    23    one is the Great Pyramid. It l    24    on the west bank of the Nile. In fact, all the pyramids along the Nile are on the west bank. The ancient Egyptians compared the rising of the sun to beginning of life and the setting of the sun to the end of life. That is w    25    their dead bodies were buried(埋葬)on the west bank of the Nile.

You can h    26    imagine how huge the Great Pyramid is. It has over 2 million blocks. Some are as heavy as five school buses. A    27    they were heavy, workers were able to put a block into the pyramid every three minutes.

The workers, Egyptian men and women, worked in teams. The teams had different t    28    . Some dug up the stones. Others moved them. Another team cut the stones. The last group put the stones into the pyramid. There were so many different teams, but the pyramid is perfect. No stone is in the w    29    position.

But how did the Egyptians move those heavy stones to the top w    30    any modern machinery(机械)? No one knows for sure. Many things about the Great Pyramid are still a mystery.