at level 28
I'm not sure if you mean Machop or Machamp... Machop evolves into Machoke at level 28. Machamp doesn't evolve but Machoke evolves into Machamp if you trade Machoke.
You Have To TRade it
If you mean by Machop, It evolves at Level 28, If you mean by Machamp, It evolves using a Link Cable!
It is suppose to evolve at the Level of 20,but if you want it to evolve later it can evolve anything after it is at Level 20.
It will evolve by level. Teddiursa will evolve into a Ursaring at level 30.
They evolve at level 36
It will evolve at level 36.
They evolve on level 40
it evolve on level on 64
if you dont let it evolve at the required level of level 20. itll try to evolve at every level following.
To evolve a Sandshrew level it up to Level 22 and it will evolve into Sandslash.
Pikachu do not evolve by level. They evolve when a thunderstone is used on them.