An observable trait, the trait that can be seen, is known as the organism's ___________

According to gate control theory, ______ sensory nerve fibers tend to "open" the gate and let pain messages through

a. small c. large b. passive d. active

Eleven-year-old Better and Hannah are best friends. According to research, they are best

friends because they a. are on the same swimming team. b. both play the piano. c. are in the same grade. d. can trust each other with secrets.