Reading Metrics
Grade Level
Middle Grades (MG 4-8)
Book Level
6.8
Points
2.0
Fiction/Nonfiction
Nonfiction
Word Count
13584
Points per Word
0.000147
Page Count
71
Points per Page
0.028169
Description
This book explains the occurrence of biological clocks, which, for example, "tell" birds when and where to migrate, plants when to unfurl their leaves, and which affect human beings in various physical and emotional ways.