Which characteristic describes an old river? a. has no meanders b. has a low stream gradient c. has no tributaries d. is near headwaters

The right option is; B. Has a low stream gradient

Has a low stream gradient is the characteristic that describes an old river.

A river is a large, natural and often winding stream which carry water down from higher areas to a lower point, ending at an ocean or in an inland sea. Some rivers are young while some are old. Rivers possess different features as they age. Old rivers usually have a low stream (gentle) gradient and low erosive energy. They usually have broad U shape, the water is usually brown and they have flood plains. Seasonal floods are also common.

it is very hard for the climatologists to precisely predict how will the global temperatures be changing so there's lots of models, some of which differ significantly, this is due to multiple factors, and probably the most important is the human activity.

humans have been a key factor in climate change around the globe since the start of the industrial revolution, and in the past few decades the consequences are becoming more obvious. there's lots of emission of pollutants in the atmosphere as well as changing the environment on the surface itself, so it's really hard to predict how will that go in the future because there's some countries that are reducing the damage and are going towards green energy, while others are stubbornly continuing with pollution and damages to the environment.