No some rivers can become wider, smaller, deeper and narrower. not all of them follow the same pattern.
no
No, rivers can have different elevations. If all rivers had the same elevation, there would be a lot fewer waterfalls!
meter or iambic pentameter
No they all differ
No, all rivers are different and no two are the same. A river will differ in numerous ways - usually always by length, by water volume etc.
No all footwear is not the same. Some follow the fashion. Some follow the safety equipment standards.
All subpoints of a particular point have the same grammatical characteristics
Not all countries will follow the same pattern of demographic transition due to variations in factors such as cultural norms, government policies, economic development, and healthcare systems. Some countries may experience different demographic trends depending on their unique circumstances.
Mostly all of them but for some exceptions
Sunlight
no unless you were to pollute all the rivers or chop down all the trees before others grew.
No the Nile is the longest if them all, they are all different lengths