Wrong orientation of surfaces when import to 3DS MAX

Hello,

My problem is that when I export surfaces or polysurfaces (extension dwg) and import them to 3DS max, some of them become dark and I need to flip them one by one. Is there any way to flip these surfaces directly in Rhino before importing?
And something more: is it possible to know which surfaces are ‘wrongly’ oriented in Rhino?

Thanks

Hello - if you set your display mode to show colored backfaces you can see the orientation in Rhino -

-Pascal