I am working on some qual questions, and I don't really comprehend this. Let $X = S^{1} V S^{1}$. The question is asking about covering spaces 7,9, 11, and 12.
a. Determine whether or not the corresponding subgroup of $\pi_{1}(X)$ is normal.
c. Compute the deck group of the covering space.
For part (a), Hatcher says "the covering spaces with maximal symmetry are normal" and then rattles off which of them are normal; however, he never defines maximal symmetry so I don't really understand.
For part (c) I am pretty stuck. I am not sure what to do.
Please help.
Thank You 
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