Deal to bring S.F. students back to classrooms leaves many questions unanswered FacebookTwitterEmail 1of7 David Thompson, Luis Tamayo and their son, Lucas, 9, head home from Adda Clevenger School in San Francisco, Calif., on Thursday, October 15, 2020.Scott Strazzante / The ChronicleShow MoreShow Less 2of7 Health Science teacher Evan Mundahl works to educate his students on the coronavirus through group project work in his first period class at Phillip and Sala Burton Academic High School in San Francisco, Calif. Wednesday, March 11, 2020.Jessica Christian/The ChronicleShow MoreShow Less 3of7 Minerva Pacheco (center) and her children Daniel Martinez Pacheco, 8, (left), Iris Martinez Pacheco, 11 and Brian Martinez Pacheco, 7 (right) prepare to go to the park on Monday, Feb. 8, 2021 in San Francisco, California.Gabrielle Lurie / The ChronicleShow MoreShow Less