The U.S. is projected to see nearly 100,000 more COVID-19 deaths between now and Dec. 1. That’s the prediction from the nation’s most closely watched forecasting model. But health experts say that toll could be cut in half if nearly everyone wore a mask in public spaces. Experts agree: What the coronavirus has in store this fall depends on human behavior. And early signs suggest behavior changes may already be flattening the curve in a few places where the virus raged this summer. An Associated Press analysis shows the rate of new cases is slowing in Mississippi, Florida, Louisiana and Arkansas.