What is your ultimate (and interestingly your first) protection against external pathogens and invaders?

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    your skin
    your stomach
    mucus
    all of the above are correct
asked May 19, 2013 in Biology by anonymous
    

1 Answer

0 votes
all of the above are correct
answered May 20, 2013 by Bioshare ~Top Expert~ (34,070 points)



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