Answer:
stomata
Explanation:
Structures in plant leaves that open and close to maintain homeostasis are stomata.
Answer:
A. 30:2
Explanation:
After every 30 chest compressions at a rate of 100 to 120 a minute, give 2 breaths.
If you touch it and it hurts that usually a sign you should not mess with it.
The heart is an example of an organ or a muscle.
Hope i helpedXD <span />
