WASHINGTON (AP) - As the U.S. enters "what may well be the toughest and deadliest period of the virus," President Joe Biden is putting forth a national COVID-19 strategy to ramp up vaccinations and testing, reopen schools and businesses and increase the use of masks — including a requirement that they be worn for travel.Biden also will address inequities in hard-hit minority communities as he signs 10 pandemic-related executive orders on Thursday, his second day in office."We need to ask average Americans to do their part," said Jeff Zients, the White House official directing the national response.