Student scientists and aspiring engineers are invited to take part in the second annual Melrose STEM Expo on Nov. 17 from 1 to 4 p.m. at Melrose Veterans Memorial Middle School. STEM is an acronym for science, technology, engineering, and math. The expo, planned by Mayor Robert J. Dolan and the Melrose Education Coalition, will feature fun, learning activities for children in grades kindergarten through 12. Students will have the chance to build and race Lego cars, robots, and other fun projects. A community sculpture, a tree made from recycled materials, will be built. People are asked to bring old paper towel and toilet paper rolls and magazines to contribute to the sculpture. To learn more about the expo or to volunteer, send an e-mail to firstname.lastname@example.org .