23. The formation of the North Atlantic Treaty Organization (NATO) and the European Union (EU) are examples of Western Europe's (1 ) responses to the oil embargo of 1974 (2) attempts to solve mutual problems (3) efforts to maintain control of colonial empires (4) struggles for economic self-reliance

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.