‏Some states authorize a to make healthcare decisions for patients who can't make them because they're incapacitated. O a) healthcare proxy b) living will O c) durable power of attorney O d) do-not-resuscitate order

genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism's offspring).

they had the law tat factories that produces smoke cannot be built near residential buildings.

building of proper sewage system was done to ensure that the waste is carried away from the humans so that they do not get diseases from it.

also they built water systems to provide water in those areas which are drought prone.

not: both offer magnification to the atomic level.