Multi combine
Combines objects of different types. For each object type, a single object containing all the selected objects of the same type is created, i.e. a curve object for all the curves, a surface object for all the surfaces, etc.
How to use
1. Select all the objects you want to combine.
2. Click the Multi combine icon or choose the Tools > Transform > Combine > Multi combine menu command.
3. See the result of this action in the World Browser.