Which belongs in each place

geologic time scale (for gradpoint) =)

sex cells are usually half's then they find another half and make a fertilize egg

sorry, is there a picture? i do not see any arrows.

wut? unius0123 wut?

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.