Earth science !

ripple marks, mud cracks and fossils are all characteristics of:
sedimentary rocks
metamorphic rocks
igneous rocks
minerals

cherts and geodes can be found in:
granite
volcanoes
limestone
silica

these rocks are often classified by their composition and texture:
sedimentary
metamorphic
igneous
minerals

these rocks can be classified as regional or contact:
sedimentary
metamorphic
igneous
minerals

the unique characteristics of sedimentary, igneous and metamorphic rocks tell us about:
how, why and where a rock formed
hot spots around the earth
weathering
movement of inorganic materials

leader‎: ‎president seat‎: ‎washington, d.c.

main organ‎: ‎cabinet legislature‎: ‎congress

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.