Missing chapters in Shiloh

Our school has multiple copies of Shiloh, published by Dell, Yearling, however the first 3 chapters are missing. These books don’t seem to have those chapters torn out. Was there a supplement that had the first 3 chapters?

No.  Your librarian should write to Dell and ask for a replacement of these misprinted books.    Perhaps your librarian bought some from a place that sells imperfect books, but this is unacceptable.