In a longitudinal study that followed a sample of American children from age 4 to 11, TV-watching predicted gains in ____

What mood disorder is characterized by alterations between periods of extremely high levels and extremely low levels of activity?

A) Bipolar disorder B) Major depressive disorder C) A manic episode D) Seasonal affective disorder

Adolescents from developedcountries who work more than 10 hours a week are more likely to ____

a. experience psychological problems b. be happy c. have several romantic relationships d. have very high grades