Pennsylvania requires everyone to wear masks when they leave the house — but the state has left business owners, transit agencies and individuals to enforce the rule, which isn’t always easy. Miles Bryan of WHYY’s Keystone Crossroads explains how hard it’s been for businesses to enforce the mask rules, and what experts say the state could do to help them. Then, Michaela Winberg with WHYY’s Billy Penn tells us what happened when SEPTA changed its strategy for how to handle this.