Impressions of leaves are recognized evidence of what pre-existing

The correct answer is - plants.

The impressions of leaves are a recognized evidence about the existence of plants plants in the geological past of the Earth, at least from certain periods onward.

The leaves themselves are very easily disposable, so it is pretty much impossible for them to be preserved in their natural form, or at least close to it. On the other hand, in certain conditions, the leaves that were disposing, managed to leave impressions, and they were kept in certain types of rocks, mainly sedimentary ones, thus providing us with evidence of their existence in the past.

i would expect light rain in pittsburgh throughout the following 24 to 48 hours. the lower/falling weights in urban areas toward the west demonstrate that a low weight framework is moving from west to east toward pittsburgh. low weight frameworks are ordinarily connected with precipitation. the way that you don't see a major drop in temperature in the more western urban areas demonstrates the low weight framework is moving with a warm front, so just light rain would be normal. substantial downpours or progressively vicious climate is just typically connected with chilly fronts, where the warm air is pushed up and over a cool front quickly. this quickly rising air (convection) is what gives you heavier torrential downpours, and other conceivably serious weather conditions.

within these regions are all the major types of biomes in the world. a biome is a community of animals and plants spreading over an extensive area with a relatively uniform climate. some diverse biomes represented in north america include desert, grassland, tundra, and coral reefs.