1) I think that walking is very useful for our health.
2) Yes, I glad that we walk on two legs instead of four because I think it's more convenient.
3) My longest distance was 100 km.
4) I believe that tightrope walking is difficult, especially when you try it for the first time.
5) I like walking around barefoot because I feel magical sensations.
6) I like to go for a walk with my friends.
7) Maybe there would be chaos. But the environment would become less dirty.