This is an image of an electrocardiogram Which statement describes the condition of the heart at the point indicated in the electrocardiogram?
(The arrow is pointed at the left slant of the peak)
The muscles of the atria depolarize.
The muscles of the ventricles depolarize.
The muscles of the atria repolarize.
The muscles of the ventricles repolarize.

The diagram shows the layers of earth. convection currents in which region influence the movement of tectonic plates

What is the main difference between the central nervous system (cns) and the peripheral nervous system (pns)? .the cns involves the brain and spinal cord, and the pns involves the body nerves. the cns involves the body nerves, and the pns involves the brain and spinal cord. the cns involves sensory neurons, and the pns involves motor neurons. the cns involves motor neurons, and the pns involves sensory neurons.

As a result of climate change earths temperature is rising and sea ice is melting what is a likely effect? answer : populations of walruses and polar bears will decline