When was the law of Population registration act of 1950 was passed , implemented and why ?​

The social difference that caused sectionalism in the antebellum era would be c.)  north was disorganized. the north had slow population growth, where as the south had mass immigration.hope this really mark

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. 

They learned to make tools.  hope this !   mark me as brainiest!