When a toddler sees a pear and says "apple", this is an example of

Which of the following most contributed to the large increase in world population that occurred around the 1800s to 1900s?

a. Families increased the average number of children per household from one to three children. b. Less women were dying in childbirth because they waited longer to have children. c. The domestication of animals provided a larger food supply. d. More people lived due to the discovery of vaccinations and medical treatments for deadly diseases.

In general, flyers or advertisements that are worded negatively, such as, "Parenting Stress

Study", often draw participants that are: A) representative of the community. B) more educated and intelligent than other parents in the community. C) more likely to drop out of your study. D) more stressed or pessimistic parents.