The endocrine system is responsible for the production of _____, molecules that influence particular organs

Although the majority of teenagers maintain stable relations with their parents throughout adolescence, as many as ___________ percent pass through a fairly rough time

a. 15 c. 25 b. 20 d. 30

The research design which investigates differences due to age, race, gender, and ethnic group,

is called the __________ research design. Fill in the blanks with correct word