How to combine smoothed polygons with hard/unsmoothed polygons?
 

Please, help me! I need this one. If you're confused and didn't understand anything, I just wanna ask how to combine smoothed polygons with a normal polygon? Because when I try to do so, the smoothed polygon(s) reverts to normal(unsmoothed).

How are you combining them? Mesh > combine?
What kind of smoothing have you done? 3 on keyboard? Try Mesh > smooth to permanently smooth the geo.
Are they going to be connected? If not, do they have to be combined?

Yeah, I combine them using Mesh > Combine. I also smoothed the object using the "3" on the keyboard.
Are you trying to ask me if the 2 objects are going to touch each other? If yes, yes, they're touching each other and yeah, they don't really have to be connected but my problem is I'm want to combine about more than 5 objects into 1 single click and afterwards I'll have to duplicate & modify them a couple of times. So I basically I just want to have them in just one click so I won't worry about leaving behind one piece when I move and modify them as a whole.

EDIT: Oh sorry! I already tried what you've said. I've just realized that "3" on the keyboard and Mesh > Smooth are different. I thought "3" was the shortcut, but it was only a preview. Many thanks! You've added a whole book of knowledge into my head.

If you want to duplicate you dont have to combine them...all you need to do is GROUP them mate. Then when you wish to move etc you select the group in the outliner...lot easier.

cheers bullet