Due to various problems including AOL's I haven't been able to read the posting regularly. I beg to differ about your view of reading in the primary grades. Sundance has sets of expository text of about 10 levels with 8 titles to a level for the emergent readers. The Wright Group and Rigby Press have numerous sets of expository text for the emergent All your major book companies have expository text on every level in their anthologies.
Teachers constantly use annologies to help children understand the unfamiliar, etc.
Primary children use the Venn diagram, the KWL charts, semantic maps, evaluate and apply their new knowledge very successfully. At every level you have your precocious children who are reading well beyond the so called grade level. Today more then ever the gap between the successful and the unsuccessful is widing. There are children who come to school ahead before they begin because their parents were so dedicated. Too many children are behind before they begin because of the ignorance or selfishness of parents.