Which process moves food through the esophagus?

Are substances released into the environment that in excess amounts cause damage

If scientists are wrong about earth's age based on radioactive material and the decay rates are really much faster, how would nuclear power plants be affected?

Why are fossils not found in igneous rocks? igneous rocks are made from cooling of lava or magma. igneous rocks are found too deep underground. igneous rocks are too dark in color to contain fossils. igneous rocks are too dense to contain fossils.