It is important to remember that with reptiles and amphibians, most of the recommendations are completely subjective and not actually based on any experimental data. The fact that he recommends supplementing foods twice a week doesn't mean it is based on any hard facts. I think that if you feed something three times a week, supplementing the foods once a week is completely sufficient if the animal is not under undue stress, has been dewormed etc. I personally prefer to supplement only one times a week because you can actually over supplement (hypervitamintosis). When it comes to pacman frogs where you feed larger meals less frequently than other frogs, supplementing the foods every other feeding should be fine.
I highly encourage you to do your best on this article. Getting literature published under your name at an early age sets you up for an easier time in college, and also in a professional career that so heavily involves writing. Keep up the good work
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...the oldest task in human history: to live on a piece of land without spoiling it."
Aldo Leopold (1938)
"Sometimes I think the surest sign that intelligent life exists elsewhere in the universe is that none of it has tried to contact us."
Calvin and Hobbes (Scientific Progress Goes 'Boink', 1991)