Acceleration is defined as the rate of change for which factor? a. time b. velocity c. position d. displacement

dopamine..

"it was found that some people who were taking the drug l-dopa to raise their levels of dopamine were developing schizophrenic-like symptoms supporting research a strength of the dopamine hypothesis is that there are many studies which have shown support for the neurochemical explanation."

3. dark matter

empty space could also be a simple vacuum