There are several ways to accommodate content reading assignments with students' varied reading levels. Rieck (1977) reported that many times content teachers simply do not expect their students to read the text. She found that tests given in content classrooms often covered only material from lectures and class discussions rather than text reading. In addition, students were rarely required to discuss their assigned readings.
Readence, J. R., & Moore, D. (1980). Differentiating Text Assignments in Content Areas: Slicing the Task. Reading Horizons, 20 (2). Retrieved from http://scholarworks.wmich.edu/reading_horizons/vol20/iss2/6