Why arent descriptive investigation repeatable

Which table best shows the impacts resulting from human activity? impact of human activities human activity impact forest area cleared to construct an airport increase in oxygen level vegetation cleared to construct an oil mine increase in pollution impact of human activities human activity impact forest area cleared to construct an airport increase in sound pollution vegetation cleared to construct a power plant contamination of water impact of human activities human activity impact beehives cleared from urban areas increase in vegetation dams constructed on a river increase in fish population impact of human activities human activity impact beehives cleared from urban areas increase in bird population dams constructed on a river better quality of water

How does buring fossil fuels impact does carbon cycle? what large impact does this have on the envirnment?

Restriction enzymes are used in making recombinant dna. describe the role restriction enzymes perform when constructing recombinant dna.