Astudent is studying mitosis , in which a cell divides to form two cells, which of these shows the correct mathematical model for the process nold shows the number of chroosomes in the parent cells and new shows the number of chromosmoes the individual daughter cells

not sure if this is what you'r looking for nnew= nold

a "theory" a suggestion that is not 100 % accurate, or a figure. some people say its a theory because they of all the passed theory's about one subject. it depends sometimes theory might be accurate and sometimes they are.

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.