References

1)my science textbook

2)a Casco Science study guide for lower sec

3)http://www.google.com.sg/imghp?hl=en&tab=wi

4)http://digestive.niddk.nih.gov/ddiseases/pubs/yrdd/

5)http://science.nationalgeographic.com/science/health-and-human-body/human-body/digestive-system-article.html

6)http://kidshealth.org/kid/htbw/digestive_system.html

7)http://www.innerbody.com/image/digeov.html

8)http://www.gesa.org.au/digestive_system.cfm

9)http://en.wikipedia.org/wiki/Digestion