Ventilation systems are needed in a <span>multicellular organism to actually obtain oxygen and give out carbon dioxide. Without this ventilation system, it would be very difficult for multicellular organisms to survive. It has been also observed that surface diffusion is not enough for a multicellular organism to breath.</span>
Answer:
[D] Pitch
Explanation:
The measure of how high or low a sound is called the pitch.
Answer:
Thymus gland
Explanation:
it is active during puberty mostly and after slowly shrinks
Answer:
If you apply too much pressure, you can cause redness and abrasions.
