Which two healthcare plans typically require patients to
see a primary care physician?
ppo and pos
ppo and traditional
hmo and traditional
hmo and pos

True blindness may be caused by trauma to the eye, severe conjunctivitis due to  ibr (infectious bovine rhinoceros) or pink eye or other infections, leptospirosis, lead poisoning, selenium toxicity, fungal infections, vitamin a  deficiencies, rabies, vitamin b12 deficiency, neoplastic of the orbit or  conjunctiva, cataracts, congenital malformations, etc. 

(pedro de cieza de leon, taken from the book chronicles of the incas) is that it's offered rewards to the empire's hardest workers.