Books with title Towns down underground

"John - I can't - go on - any - longer," Mary panted, as her steps began getting very slow. John looked over his shoulder and saw that the men who were chasing them were getting uncomfortably close.John, Mary, Andy and Jane plan to have a fun little camping party in the meadow a little ways from their house. But once they decide to explore a strange cave that Jane discovers, they find that it could be harder to get back home than it was to come away.About the SeriesThe Four Children's Adventure Series follows the adventures of four brothers and sisters from the same family: Mary, John, Jane and Andy. The fictional adventures are geared toward children ages 10-16. You will find no disrespect of parents, no violence, no sorcery, no evolution, and no humanism in these wholesome books for kids.About the AuthorAnisa Joy Razvi, at 14 years old, lives with her parents and eleven siblings in a rural area of Maryland. Anisa has a personal faith in the Lord Jesus. She is the editor for Conquered By Love books and assists that ministry in many other ways. Anisa was homeschooled and appreciates the flexibility in homeschooling which allowed her to begin college at age 13. Anisa plays the piano, violin, and harp. She has a special interest in history, and enjoys reading, singing, drawing, and spending time outdoors. Anisa enjoys telling stories to her sisters, and the Four Children’s Adventure Series grew out of the stories that she has told them over the years.

Coal is burned to make electricity. Iron is used to make steel. Electrical wiring is made from copper. Stone and sand are needed for building. These important materials and others like them make our lives easier, but they are not easy to get because they have to be dug out of the ground. The first miners used picks and shovels. Mining has changed a lot since then.