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which statement describes the condition of the heart at the point indicated in the electrocardiogram?

a. the atria are contracting and pushing blood into the bottom ventricles of the heart.

b. the valves of the aorta and pulmonary artery close, producing the first heartbeat.

Suppose you could go back in time to interview henri becquerel on the day he discovered radioactivity. from his perspective, write an account of the discovery.

The sea slug that considered to be a photosyntheesizing animal

Many body systems work together for proper functioning of the body and to maintain internal homeostasis. the works to break down food eaten before exercising. the takes in the nutrients obtained from the food. the body sweats as a mechanism to cool off, because the is working to flush out toxins.