I think the answer is <span>epithelial and connective tissue
Muscle cells need much energy to moves its fiber, so it must be on a highly vascularized area. The nervous system also needs a blood supply to works. In fact, the brain cells use the highest amount of energy.
Epithelial and connective tissue doesn't need much energy because its main function is to protect other tissue. It also has densely packed cells to make it sturdy.</span>
Microfilaments
Microfilaments are fine, thread-like protein fibers, 3-6 nm in diameter. They are composed predominantly of a contractile protein called actin, which is the most abundant cellular protein. Microfilaments' association with the protein myosin is responsible for muscle contraction. Microfilaments can also carry out cellular movements including gliding, contraction, and cytokinesis.
Microtubules
Microtubules are cylindrical tubes, 20-25 nm in diameter. They are composed of subunits of the protein tubulin--these subunits are termed alpha and beta. Microtubules act as a scaffold to determine cell shape, and provide a set of "tracks" for cell organelles and vesicles to move on. Microtubules also form the spindle fibers for separating chromosomes during mitosis. When arranged in geometric patterns inside flagella and cilia, they are used for locomotion.
Hope this helps :)
Physics is very common in our lives, and of course this also applies to the performance of a runner.
For example, he or she needs to understand the air resistance when running, they may need to find a way to reduce the most air resistance that is against them so that they can show their best performance.
Or another example is they may need to find out the friction acting on between their feet and the track, they may need to adjust their training in different textures of running tracks, as each acts a different amount of friction.
B. Independent meaning by itself. Dependent meaning together, or not by itself, and since both are going 60mph and they both stop it’s dependent because they’re depending on each other to stop.
