National parks reduce the human impact on land by preventing human development.
<span>pressure , heat and erosion
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Hey!
Elders have several medical issues, such as arthritis, cancer, heart disease,diabetes. There are even mental ones such as dementia, or <span>Alzheimer's disease. However, some of them go unknown like cancer, until tests are ran or you have skin cancer and you develop outside lumps. However, mental illnesses are usually simple to diagnose. Sometimes, they might forgot your name, or where they are. They just stare at nothing, or they talk to themselves and wander around. People who age do forget more things, but they are usually alert and aware of their surroundings.
Hope this help!</span>
The answer to this question would be: <span>B. Receptor site
The receptor site of a neurotransmitter often only receives a specific kind of transmitter. That was because the receptor has a unique 3D structure, so different transmitter wouldn't fit into the receptor. That was similar to lock and key principles.</span>
