PLEASE HELP
why did SARS-CoV-19 pandemic occur or happen?

Group of genes that encode molecules found in all body cells, creating a biochemical “fingerprint” that serves as the “id” for cells so that they are marked as “self” a) deoxyribonucleic acid (dna) b) entry inhibitors c) major histocompatibility complex (mhc) d) non-nucleoside reverse transcription inhibitors (nnrtis)

In a paragraph describe the function the stomach serves in the digestive system

Which is shown to be an effective treatment for depression?