I've read someone from US commenting on a great picture by saying "Holy mac and cheese!". So I guess it means "Wow, that's amazing!"

I always love every step I make. While I am doing that I would rather focus on the 'journey' itself. In this case, I should concern more about the essence by learning here, rather than only collecting the points. Observing is always interesting for me. I hope you follow me. Good morning with blessings!

Thank you! I always appreciate your guidance to improve my English. Please tell me if you have your own site/blog so I could explore more of my English knowledge, I would join. Blessings!!!

Thank you. Yes, the consideration is although some researches have passed (marked by the year) but the results still happen until today, and some others will be in the future. I am giving you another example: "From those two species, C. ledgeriana is chosen for its economic value, because it is believed to have the highest quinine content amongst the plants in the genus Cinchona (Maehara 2011)." What is your opinion?

@J.R. The 'clue' is on my profile page, or let me know yours. Thanks so much for your efforts!

@StoneyB Perhaps 'Dang' also could be included? It is kind of a region characteristic in US?

@Matt I notice this 'howdy howdy' is an informal greeting, while for 'how do you do' as I learn (I am a non native speaker) is a formal greeting when you firstly meet with someone.