More than 500 students are showing off what they know about science. The Bossier Civic Center is the site for this year's Louisiana Regional Science and Engeneering Fair. Students in grades 4-12 from five parishes are participating. Everyone will be judged by 135 regional professionals. The science fair runs through Saturday. It will wrap up with an awards ceremony, and winners will qualify for the Louisiana State Science Fair in Baton Rouge at the end of the month.