Name 3 contraceptive methods and their functions, and how effective they are in preventing unwanted pregnancies. 

INSTRUCTIONS: Answer all questions. For each question, your answer should be detailed, not exceeding 300 words. Supporting your responses with current examples will earn you more points.

1.Describe what is meant by the process called secondary succession

2. Name 3 contraceptive methods and their functions, and how effective they are in preventing unwanted pregnancies.

3. Describe traditional methods for enriching or recovering soils

4. Why do children tend to be more susceptible to environmental toxins?

5. What actions have been taken to reduce lead exposure?