AT - Find the cohomology ring of the loop space of CP^n and RP^n. Use spectral sequences.
AT - Where does the 7-torsion appear first in the homotopy groups of S^n.
AT - Which RP^n, are orientable ? Why ? Use Stieffel-Whitney classes. 
AT - What is your favourite definition of orientability ? Define the orientation character. 
	Give applications of Alexander duality.