Answer:a better understanding of potential research problems
Explanation:
The answer is D. We use oxygen to breathe and make carbon dioxide . Plants take the carbon dioxide to photosynthesis and make oxygen.
Answer: b. African Americans
Explanation:
According to available information, this racial group has the highest divorce rate in the United States. Many factors affect the divorce. Premarital non-education, religious differences, financial problems, lack of family support, health problems, domestic violence, early marriage, adultery are some of the main factors that lead to divorce.
D. Calculating how much income was paid in the previous year
