The condition known as heartburn is most often caused by acid regurgitating from the stomach into the esophagus. why do you think the acid tends to burn the esophagus and produce pain but does not similarly burn the stomach?

what have scientists found to be the most efficient and effective way to insert new sequences into an individual? a-scientists have created genetically altered foods that release dna during digestion. b-scientists use viruses to insert specific gene sequences. c-scientists irradiate genes so that they can be absorbed through the skin.

is this for the e2020 class