Two teenagers appeared in a London court on Friday after an investigation into suspected extreme right-wing terrorism, involving allegations of attempting to acquire firearms and explosives. Rex Clark, 18, and Sofija Vinogradova, 19, were both charged with a single count of preparation of terrorist acts, after an investigation which was not linked to riots and racist attacks which took place across Britain last month, London’s Metropolitan Police said. Clark’s alleged offending relates to “the acquisition and construction of component parts of (improvised explosive devices), the making and tes…