Answer:
The heart is a pump, usually beating about 60 to 100 times per minute. With each heartbeat, the heart sends blood throughout our bodies, carrying oxygen ... It sends out an electrical signal to start the contracting (pumping) of the heart muscle.
Explanation:
Answer:
Hypothesis If the type of the food available changes, then the frequency of beak types will change, because birds with beaks more suited to the available food will be more successful over time.
Explanation:
Answer:
<em>i</em><em> </em><em>gu</em><em>ess</em><em> </em><em>it</em><em>'s</em><em> </em><em>gender</em>
<em>hop</em><em>e</em><em> this</em><em> helps</em>