By DEE-ANN DURBIN, AP Business Writer Coca-Cola's revenue plunged 28% in the second quarter, but the company thinks the worst could be behind it. Coke Chairman and CEO James Quincey said sales improved sequentially in May, June and July despite surging cases in key markets like the U.S., Iran and Australia. While the path forward is unclear and the global economic recovery will take years, Quincey