ORh+ human being can donate his/her blood to?

blood group type O negative blood is the variety of blood that has the lowest risk of causing serious reactions for most people who receive it.

Explanation:

answer: i cant find your answer. do u have another way i can answer it for you : )

explanation:

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.