The Paris Olympics promised to be the greenest in history. Can they deliver?

Organisers promised that the Paris Olympic Games would be the greenest in modern history, saying they would halve the carbon footprints of the London and Rio editions. Can sporting events of this size be environmentally sustainable? If not, what might an alternative look like? Sticking with the Olympics, the women's boxing has been generating plenty of discussion. Algerian fighter Imane Khelif has guaranteed herself a medal but why is it her gender that everyone wants to talk about? And the National Party has announced changes to how maths will be taught to our kids. They come into effect next year; how are teachers feeling?