We can't possibly perceive the countless stimuli around us at any given moment so we utilize to focus on limited aspects of our experiences.

A) visual capture
B) perceptual constancy
C) selective attention
D) cocktail party effect

. ph changes the ability of them he enzyme to dissolve in water.

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.