What is the neuron's refractory period? O when Na* channels in the axon hillock open, allowing positive ions to enter the cell.
O a period when a neuron cannot produce another action potential because its potassium channels will not open
O a period when a neuron cannot produce another action potential because its sodium channels will not open

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

Paint and solvents pose no potential hazard to human health. select the best answer from the choices provided t f

Moving down the ramp from 6 meters to