How does a threshold prevent a neuron from generating too many action potentials

When elements that form a mineral dissolve in hot water, they form a mixture called a(n) a)geode b)vein c)evaporation d)crystallization e)magma f)lava g)solution h)gem

Me with biology endocrine system crossword also image left i need with hw

Which of the following are not included as modern mammals that evolved during the eocene epoch? primates artiodactyls perissodactyls none of the above