<span>The motor unit that is activated first and takes less energy is classified as low-threshold. The motor unit that is activated second and takes more energy is classified as high threshold. Sol lifting the labbook and placing it in the book bag simulates more motore units.</span>
A concentration gradient is a process of particles, which are sometimes called solutes, moving through a solution or gas from an area with a higher number of particles to an area with a lower number of particles. The areas are separated by a membrane.
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People would have to plant more, people could die, animals could die.