Hummingbirds can fly as fast as 60 miles per hour. One reason why its a scientific question is because of their speed. Their speed is very different compared to many other animals. I hope this helps :)
Answer:
Pacemaker cells are located in the <u>sinoatrial node.</u>
Contractile cells are located in the <u>Heart</u>
Explanation:
The one that needs help
hope that helps
Answer:
The answer is A
Explanation:
Because available energy decreases as you go up
