In science, an educated guess is a
a. hypothesis
b. theory
c. both a hypothesis and a theory
d. smart

Hypothesis

Explanation:

In science they use hypothesis as an educated guess because you are using facts and statistics to find the outcome/answer of the original question.

i am positive it is c. condensing but i may be wrong

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.