If you were studying the effects of success and failure on feelings of depression and all of the participants experienced the failure condition on a rainy Monday and the success condition on a sunny Wednesday, ______ might be a threat to internal validity

Regarding teratogens, which of the following statements is FALSE?

a. No direct intermixing of blood takes place between a mother and her unborn child. b. If a mother is addicted to morphine, heroin, or methadone, her baby may be born with an addiction. c. Children with fetal alcohol syndrome are born with fluid on the brain and an abnormally large head. d. Children of smoking mothers score lower on tests of language and mental ability.

About what percentage of single-parent homes in the U.S. is single-father families?

a. 6%. c. 19%. b. 10%. d. 40%.