We’re thinking of Dad ahead of Father’s Day at a time when the number single father families nationwide has nearly doubled since 1990. Angelo Marinosci is a listener in Warren, Rhode Island, who hears us on WGBH. He’s 64 with a 5-year-old son. And Bob Murgo, Takeaway listener in Newport, Rhode Island is a 59-year-old and a former single dad. His daughters are now 37 and 38. They talk about what makes a good single father.