Science Class Dr. Mark Tschopp, a materials engineer at the U.S. Army Research Laboratory, poses with a fourth grade class at Homestead-Wakefield Elementary School in Abingdon, Md., April 7, 2017. Courtesy photo SHARE: Download: Full Size (0.17 MB) Tags: science, technology Credit: Courtesy photo VIRIN: 170501-D-XT155-001.JPG Photo Gallery