How will the people of paradise have 2 wives if they had only one wife in this world?

According to prophet, 70,000 people from his ummah will enter jannah without reckoning, among them each will have 2 wives, what does it mean by 2 wives?? Does it mean that the 70,000 people will be only men not women?? What if a man has only one wife in this world then who will be the second wife??