Answer:
Starts in a group of cells at the top of your heart called the sinoatrial (SA) node. The signal then travels down through your heart, triggering first your two atria and then your two ventricles. ... The SA node (called the pacemaker of the heart) sends out an electrical impulse.
Explanation:
Answer: <span>Garments that protect extremities
</span>
<span>During cold weather, the most important thing
for a person to look for is an exercising clothing that can protect the extremities so that you will not experience hypothermia, frostbite and generalized vasoconstriction, which are dangerous to your health.
Therefore, choosing the right garment will allow your body to give off heat during exercise in cold weather and maintain body heat during rest. Moreover, wool is a good fabric that could retain body heat.</span>
One-quarter to one-third, hope this helped :)
B is incorrect if I’m sure yeah.