Importing and closing shapes problem in sketchup

I have a problem when i import dwg file to SU the lines get to be unconnected and some of them disappear and i cant close the plan because of this
Any help with this?

رفع.dwg (131.1 KB)

Have you checked the scale at which you imported the drawing?

There are also a few problems with the drawing, some portions are at a different level than 0.