Read and fill in.Thirty days has S_p__mb__,A___l,_un_ and N__e_b__.All the fast

Read and fill in.
Thirty days has S_p__mb__,
A___l,_un_ and N__e_b__.
All the fast have thirty-one,
Expert for Fe_r__r_ alone
Which has twenty-eight days clear
And twenty-nine days each leap year!
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