Hi, naty16. You have selected a quite interesting topic to be discussed with. If I were you:

• I would make the text alignment either left aligned or justify.
• I would cite my article references and images' references.
• I would look into some topic that suggested a smile has a positive correlation with longevity and discuss its scientific explanation.

If you have any problem regarding STEM-related articles, you can join steemSTEM Discord Channel and we will be glad to assist you.