River in PG Uber Scenario 4

[g1ul10]

Indeed. Very useful advice.  But you guys are far ahead of me :-) I've still some basic "facts" to digest. Let me try to rephrase my questions in a more direct way:

Question 1: When I see a river on the map, as it is the case with PG Uber Scenario 4, and the scenario sheet says nothing about it, should I assume it is a major or a minor river?

Question 2: Is it correct that no units can cross a major river without the help of engineers?

Question 3: Is it correct that, in case of minor rivers, leg and track can cross them, albeit at a cost, while motorized units still need the help of engineers?