1. Well, what happens? You tell me. Wait, if you knew, why would you be here? Oops, Sorry.
Anyway, what do Red  Blood Cells do? They carry oxygen around the body right? How? Oxygen can combine with the Hamoeglobin in Red Blood cells to form what they call, Oxy-hamoeglobin.

So an appropriate answer would be, Red blood cells 'take up oxygen' and becomes oxy-hamoeglobin.Right?

b) What do White Blood Cells do? In GCSE level, they essentially produce two types of antibodies, Lymphocytes and Phagocytes, to protect the body from pathogens, bacteria, harmful stuff. So that's probably what its existence in the alveolus is for. PROTECT THE LUNG FROM PATHOGENS!!!