useless trivia: What Word Means: A Pony?

Questions

hydroxydesoxycorticosterone and hydroxydeoxycorticosterones are the largest----------?

if you look carefully at the picture of mona lisa, you will notice a ---------- in the background?

in english, ---------- is the only digit that has the same number of letters as its value?

10?

in the---------- , mabuhay means hello?