Answer:
Small and tube shaped, water enters the sponge through dermal pores and flows into the atrium. Choanocyte flagella create the current to expel it through a single osculum. Note that water enters the sponge through a modified cell known as a porocyte.
Explanation:
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Viruses need to be inside a living thing (of course the living thing has to have the right temperature which most living things do) . When they're inside a living thing they start injecting the host's cells with its DNA in order to make more copies of itself which allows the virus to spread. So basically viruses need to be inside something living.
Maybe, not sure, may need to check yahoo answers for this one