Concrete is a mixture of cement, water, sand, gravel, crushed rock, or other aggregates. Sometimes, one or more admixtures are added to change certain characteristics of the concrete, such as workability, durability, and time of hardening.
Top 100 Colleges by Highest Tuition. Here are the top 100 most expensive colleges by tuition for the 2008-2009 school year. The latest numbers can be found in our most expensive colleges ranking. Notes: Some colleges like Bates College, Colby College, Middlebury College, and Union College have a comprehensive fee (tuition + room/board).
List of the largest United States colleges and universities by enrollment. The ten largest colleges and universities by enrollment in the United States. This is a list of the largest United States colleges and universities by enrollment for colleges and universities in the United States. Enrollment is counted by the Integrated Post-secondary Education System within the U.S. Department of Education.