Dotted Lines Instead of Solid Appear when I Export from SketchUp to PDF

Hello, I have seen this issue reported here but no response. When I export my file from SketchUp into a PDF some lines that were solid in SketchUp suddenly appear as dashed. Please help! I have an assignment due for school and can’t use photoshop because of this issue.

Share your SketchUp file and your PDF so we can see what you are starting with and what you are getting.

Thanks for replying!
LAEP_6100_MasterPlan_Sketchup_Apr18.skp (7.2 MB)
LAEP_6100_MasterPlan_Sketchup_Apr18.pdf (514.8 KB)

I’m not seeing the reason for the dotted lines but I do see them. It may have to do with the size of the model. I sent the file to LayOut and exported from there and I get much better results. See this:
Master Plan.pdf (141.1 KB)

Thank you so much for taking the time to do that for me! That was very kind of you. I opened in SketchUp and it does what I need! Wow - what a cool forum!