Across
- 5. two's a crowd
- 7. Dinner for Mr. Macrophage
- 8. the engulfing of invasive pathogens
- 9. secreted proteins with a purpose
Down
- 1. where white blood cells are made
- 2. a respiratory passage in the body
- 3. protective slime in respiratory system
- 4. tiny air sacs in the lungs
- 6. molecule needed for metabolic work