Mo and Jo are cavemen who, in three easy-to-read chapters, try to improve the smell of themselves and their cave, attempt to play hide-and-seek, and discover that there is more than one way to stay warm on a cold day. Interest Level: K-3 Reading Level: 1.0 ATOS Book Level: 1.7 AR Interest Level: LG AR Points: .5 AR Quiz: 181534EN Lexile Code: BR (Beginning Reader). Teaching Books: https://school.teachingbooks.net/tb.cgi?tid=48077.