Adna sequence found at the beginning of a gene; indicates the place where the copying of the gene will begin

i won't lie i don't know so go online and ask google thats what i do

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.