4, true
5, false.
6, true
7, true
hope this helps!
Takeoff. Generally, a right-handed long jumper takes off with the left foot. New jumpers may wish to try both to which style works best. When you hit the takeoff board, your body will actually be leaning slightly backward, with your foot in front, your hips slightly behind and your shoulders a bit behind your hips.
Mark as brainlist
Cardiac-muscle cells are striated<span>, and are a lot like skeletal-muscle </span>cells<span> except that in cardiac muscle, the fibers are </span>interconnected<span>. The </span>sarcoplasmic reticulum<span> of cardiac-muscle cells is not as well-developed as that of skeletal-muscle cells. Cardiac-muscle contraction is </span>actin-regulated<span>, meaning that the calcium ions come both from the sarcoplasmic reticulum (as in skeletal muscle) and from outside the cell (as in smooth muscle). Otherwise, the chain of events that occurs in cardiac-muscle contraction is similar to that of skeletal muscle.</span>
