Just ask a question so we could answer it...
The numbers 1,2,3 that is connected to "Barriers", maybe you should write the parts,or what you think is the barriers
Hope this helps
Communication is a brpad topic. Without the knowledge or backgroud of it you cant answer that. Try to scan your book to find an answer depending on someone is not good. Try to stand on your own.
the Public Land Survey System (PLSS) is a way of subdiving and describing land in the United States . All lands in the public domain are subject to subdivision by this rectangular system of surveys,which is regulated by the U.S. Department of the Interior ,Bereauof the Land Management (BLM)