Select three situations in which unbalanced forces are acting on the objects.

this protocol provides a detailed procedure for agarose-based ip to purify and enrich the protein of interest.

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.