Making Terrain Flat

[Trotskygrad]

so I've searched for how to do this, and I can't find it

say you've made an area bumpy, and now want to flatten it. There was a specific tool to do this in Sim city 4 and BF2's terrain editor (That's what this sorta reminds me of, lol), is there a specific way to flatten terrain in the MoW editor?

thanks in advance for replies.