By Daniel Kline The pandemic has been a moving target, but cruise lines Carnival and Royal Caribbean have continued to make progress. The covid pandemic quickly went from a minor inconvenience to an event that shook the entire world. In March 2020, as the virus first became known, businesses shut down, people began isolating, and we all started hearing about wearing masks. It all seemed temporary because the idea that the world would close down — at least partly — for more than a year seemed unthinkable. But people began to work from home. And among so many other changes, restaurants closed …