<span>3. Reduced bone marrow in the spongy bone.</span>
Answer:
The sternum, thoracic vertebrae, and ribs protect the heart and lungs.
Explanation:
The skeleton can be divided into the <em>axial skeleton</em> (the skull and the vertebral column), <em>visceral skeleton</em> (ribs and sternum) and the <em>appendicular skeleton</em> (extremities).
The function of the <em><u>visceral skeleton</u></em> is to <em>support and protect</em> the first portion of the digestive and cardio-breathing apparatus.
In mammals, the second part of the vertebral column (thoracic vertebrae), the ribs and the sternum delimitate a protective box for lungs and heart.
2. Cell (Plasma) membrane
4. A cell membrane is made of phospholipids, is flexible, and is found in animal cells. A cell wall is made of cellulose, is rigid, and is found in plant cells.
1 tropical rain forest
2 tropical dry forest
3 desert
thats all i know :)