"Pick Lines" tool not identifying some curves

[gaitan94]

I imported a dwg file I draw in rhino in order to model the floors of my project in Revit. but when I try to use the "pick Lines" tool to create the contour of the floor there are some curves that I cant pick and some that I can, someone knows why this happens and how too solve it?

[barthbradley]

Try TAB-Select on one line that you can select and see if it picks them all up at the same time.   

[constantin.stroescu]

it doesn't work for splines....

In order to solve the problem : 

• in AutoCAD  select the splines and use command Flatten
• save the file and open it again in Revit as a succession of small curves -you will can use now Pick Lines tool

[andrea.grillo]

What about people on Autocad LT?
We don't have the "Flatten" command.

How do we fix this?