Toddlers become better at using what perceptual system to adjust their walking and running in response to changes in surfaces?

In Prof. Bilgrim's research project, teens from India, Turkey, and Canada are observed in a normative social influence situation. The data from the three groups are then compared. This is best described as a(n) _____ study

A) multiethnic B) cross-cultural C) ethnological D) observational

A condition in which the bones become brittle, fragile, and thin, often brought about by a lack of calcium in the diet is called

a) osteopathy. b) endocrinology. c) osteoporosis. d) rickets.