Here's to the heroes who keep our world clean. From roadkill collectors to landfill gas operators, these workers get dirty to keep us healthy and safe. Readers will explore some of the most disgusting waste-related jobs, down to the dirty details. They'll enjoy this high-interest topic so much they won't realize they're learning important information about STEM jobs.

Where can you get paid to deal with pet food, fish guts and organ meat? In the food industry! Readers will explore some of the most disgusting food-related jobs, down to the dirty details. They'll enjoy this high-interest topic so much they won't realize they're learning important information about STEM jobs.

A lot of people have to get dirty in order to keep our water clean. From city sewage workers to portable toilet cleaners, readers will learn all the dirty details of jobs working with water and sewers. They'll enjoy this high-interest topic so much they won't realize they're learning important information about STEM jobs.

Welcome to Russia! Look at the fairy-tale castles of Moscow. Search forests for endangered Siberian tigers. Learn about the people, places and traditions of the world's largest country.

Welcome to Syria! Picnic with locals at the ancient ruins of Palmyra. Taste rich foods such as kibbeh and fattoush. Learn about the people, places and traditions of this fascinating Middle Eastern country.