Purchase the Root-Smart book to get all 57 roots with sentence completion exercises. The answer key is free.
Root-Smart Sentence Completions Workbook
This book contains 57 of the most essential root parts your children need in order to understand thousands of words they read. Each chapter provides the definition of the root along with sentence completion exercises to help the students understand words that have been derived from that root. Students will use the context of the sentence and the meanings of the roots to select synonyms that complete the sentence.