This has been developed to prepare students for standardized testing over the Common Core Standards in English (grammar and writing) for fifth grade specifically. The passage comes from http://www.ncsu.edu/project/lancet/fifth.htm and has been edited to create questions from. There are 10 questions related to grammar and editing. There are also 10 questions concerning vocabulary (which you can change to fit your needs). There is also a writing task in the format that GA is presenting. There is a short answer, a paragraph prompt, and a narrative prompt.
You are not paying for the passages, but rather the time and effort it took to create questions, label them with standards, and compile and edit the document for student use.