Beginner help with inventor

[jmmealer22]

I am trying to teach myself the uses of intentor. I have some drawings on AutoCAD and want to bring them into Inventor to work on some assemblies. My problem is that only some of the objects from my drawings are imported into Inventor. I don't know the reason why only some of the drawings go in while others don't. 

I was hoping someone could shed some light on this and maybe give me some rules for importing from CAD to inventor.

Thanks...

I'll also attach the drawing I am practicing with

[MingweiGao]

Hello,

It seems you have some surfaces in your DWG file. You can try to check the New Part option below Destination for 2D data and then check the Surface option below 3D data options during the Import Destination Options dialog.

Please refer to the attached picture.