Engage your most struggling readers in grades 3-6 with Red Rhino Nonfiction This new series features high-interest topics in every content area. Visually appealing full-color photographs and illustrations, fun facts, and short chapters keep emerging readers focused. Written at a 1.5-1.9 readability level, these books include pre-reading comprehension questions and a 20-word glossary for comprehension support. Are there white holes in space? Who said space and time are the same? Why do wormholes exist? How fast does light travel? What if you could time travel?