Scientists realized each person's DNA is different in 1984.

True
False

True!

By the 1940s scientists realised that DNA contained the code for life, and in 1953 Watson and Crick at Cambridge University discovered how information was stored in DNA and transferred to the next generation. In 1984 Professor Alec Jeffreys discovered the variations in DNA, unique to each individual.

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.