PBS
Pbs: American Experience: The Center of the World: Teacher's Guide
Students will have an opportunity to create memorials at the World Trade Center site to commemorate the September 11th attacks. Come and check it out.
Other
Rensselaer Polytechnic Institute: Leaching
An informative site describing the process of leaching, including links to diagrams which illustrate the process. The health risks posed by leaching are touched upon.