bone marrow <span>contains hematopoietic stem cells, which give rise to the three classes of blood cells that are found in the circulation: white blood cells (leukocytes), red blood cells (erythrocytes), and platelets (thrombocytes)</span>
Answer: Pretty sure oxygen i think not exactly sure but i think it is
Explanation:
Answer:
The letter order should be 1,4,2,3
1 goes to Q1
2 goes to Q4
3 goes to Q2
4 goes to Q3