After three successful stages in Denmark, the Tour de France cycle race returns home on Tuesday, with sprint specialist Wout van Aert narrowly leading from Yves Lampaert and Tadej Pogacar. There's a long way to go. We look at some of the key challenges coming up.
Every stage of the Tour de France is important, but some are more important than others. The crucial question is who will be wearing the race-leader's yellow jersey when the survivors arrive at the finish line in Paris on 24 July.
