The half life of uranium-235 is 4.5 billion years. If 0.5 half-lives have elapsed, how many years have gone by?

b exhibiting favoritism toward the kikuyu people.

it's c.us forest service

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.

i think its both a and b