Prairie dogs are a species whose very presence contributes to the existence of the ecosystem in which it lives. Prairie dogs contribute to the soil and water quality in their plains ecosystem. Their foraging retains water in the soil and forces fresh new grasses to continually grow. Young grasses have more nutrients for species such as bison and elk. Prairie dogs are an example of:

one centimetre is equal to 0.01 metres

hydrogen is a compound or a single element and a element is a pure substence that cannot be separated into simpler subtances

clorine is a compound its a chemical substance that forms when two or more different elements combine

so both hydrogen and clorine are compounds

the contamination

we are putting to many trash.

these muscles maintain the blood pressure in the vessels. the smooth muscles are innervated by nerves of the autonomic nervous system. when the muscles contract, they cause vasoconstriction of the vessels and increase blood pressure. when the muscles relax, they enable vasodilation of the   blood vessels hence reduce blood pressure.