Answer:
sphincter
Explanation:
circular muscle that normally maintains constriction of a natural body passage or orifice and which relaxes as required by normal physiological functioning.
Answer:
It has a negative impact on the environment by allowing toxic chemicals to harm wildlife.
Explanation:
Mining refers to the act of extracting minerals and other valuable solids from the earth's crust. The process of mining can have adverse effect on an ecosystem in the sense that wildlife is threatened during the process.
During the mining process, chemicals, which are toxic to living organisms, from the minerals gets washed into the areas surrounding the mining site. Thereby, causing serious harm to the wildlife living in those areas.
Helium could hold 2 neutrons in its nucleus.
In an ecosystem, all the trophic level in a food web are closely interlinked and any change in one level is bound to affect the other levels. The various trophic levels may correspond to producers (such as grass and plants), primary consumers (such as deer), secondary consumers (such as tigers or lions, etc.), etc. If we reduce the land available or necessary for sustaining the ecosystem by half (5 acres instead of 10 acres).
