What is meant by contingency, as a variable of reinforcer effectiveness

What effect do stimulants, such as cocaine, have on the nervous system? o a. stimulants change the activity of neurotransmitters. o b. stimulants mimic hormones and influence moods. o o c. stimulant|mchange how sensory information is processed. d. stimulants decrease brain activity.

In a two to three page paper, examine the history and development of the healthy people initiatives. discuss some of the successes and shortfalls of the three initiatives thus far; including healthy people 2000, healthy people 2010, and healthy people 2020. be sure to include statistical data from the initiatives to support your position. don't forget to cite your sources.

What should you sprinkle on cut fruits to slow the browning process? a.oil b. lemon juice or acids c.salt d.melted butter