useless trivia: What Word Means: To Pluck Feathers From A Bird?

Questions

ghosts appear in 4 shakespearian plays; julius caesar, richard iii, hamlet and----------?

---------- is to watch people eating in hopes that they will offer you some?

groaking is to watch people ---------- in hopes that they will offer you some?

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

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