What neurotransmitter is linked to opiate addiction and why

Effective communication consists of a. verbal and nonverbal communication and speaking clearly and loudly b. verbal communication and stereotyping c. verbal and nonverbal communication and active listening skills d. nonverbal communication and minimal interruptions   select the best answer from the choices provided.

If you are having a hard time lifting something, you should arch your back. a. true b. false

Which field of study contributes ideas and concepts to biomechanics?