Chapter books are usually works of fiction of moderate length and complexity.

章节书一般是虚构故事型的，长度和复杂度都比较适中。

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Amazon said the acquisition creates the foundation for Amazon Publishing to further expand into picture books, chapter books and young adult novels.

FORBES: Amazon.com Buys Children's Book Titles

My kids have entered that nebulous no-mans-zone known as the middle grade (or tween) years: too old for simple chapter books (like The Magic Tree House series), but too young to demolish YA books about vampires by the dozen.

FORBES: Not Ready for Vampires? Laurel Snyder Writes Great Books for Tweens

But no one, with the possible exception of students, will want to buy a single chapter of most books.

NEWYORKER: Publish or Perish