Black widow spider venom acts as a(n)

a. acetylcholine agonist

Whenever you have a tooth filled, you either pinch yourself or dig a fingernail into your knuckle while the dentist is working. In order to control pain, you are using

a. sensory conflict. b. counterirritation. c. systematic desensitization. d. sensory adaptation.

A researcher measures the number of birds belonging to each of 5 different species sighted in a particular nature preserve over a three month period. What kind of research is this?

a. correlational b. experimental c. relational. d. observational