The Humans - World 3, Level 3 - Need Help!

Can anyone help me with World 3 Level 3 of The Humans? No mater what I do, I cannot complete the level. Thanks in advance.

We need more information. What specific part of the level etc. Your question is too vague :)

Thanks anyway, but I was able to figure it out. You need the Witchdoctor to change one of the caveman into a wheel, and have the other caveman use it to complete the objective.