Despite thousands of U.S. schools, including in some major cities, delaying this week’s scheduled return to classrooms and switching to remote learning amid rising COVID-19 cases, officials in New York are vowing to keep schools open. “We are going to keep our schools open and ensure that our children are safe in a safe environment,” New York City Mayor Eric Adams, who took office over the weekend, told reporters after visiting an elementary school in the Bronx on Monday. New York City schools, the largest district in the country, reopened as planned on Monday but with more testing for its nearly 1 million students. Instead of quarantining an entire classroom if one person tests positive, all students in the class will be given rapid at-home tests to use over the next seven days. Adams said the safest place for children was in a school building. “If you look last year …