Caves are formed by the actions of
acid rain
plant roots
river water
groundwater

Option 4. Caves are formed by the actions of groundwater.

Explanation:

Caves are form from just two ingredients: rocks and water. When rocks such as limestone, gypsum or dolomite dissolute due to groundwater going through them the process beings. Groundwater is rain water that has perforated the soil. The acidic groundwater mixed with particles of organic material that comes from dead plants starts to eat through the rock and after several hundred years or even thousands of years, a cave is formed.

good thing- during decomposition the organic molecules in organic matter are broken down into simpler organic molecules that require further decomposition or into mineralised nutrients

bad thing- it can be harmful in crop productivity

there are mainly three domains in biological classification namely; archaea, bacteria, and eukarya.

archaea includes all the prokaryotic cells which are characterized by their lipid membranes. they have branched hydrocarbon which is attached to glycerol through an ether linkage.

bacteria includes all the prokaryotic cells, the cell membrane of which are made up of the unbranched fatty acid chain. in addition, they are attached to glycerol through an ester bond.

eukarya includes all the eukaryotic cells, that is, the cells contain a nucleus and other membrane-bound cell organelles.

they can be autotrophic as well as heterotrophic, unicellular as well as multicellular

they include kingdoms like protista, plantae, animalia, fungi et cetera.

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explanation: