Three educational adventures in one volume! Modern day kids, Annie and Nico, travel way back in time to ancient Egypt and the great pyramids. That's 4,500 years ago, to when the Great Pyramid of Giza, the biggest pyramid in the world, was built. Then, Annie and Nico check out the Great Wall of China, another impressive architectural feat. Finally, Annie and Nico go back in time to learn about "black gold," otherwise known as oil, a non-renewable...