Which organism has a nerve net? a fish b hydra c flatworm d sponge

In all living cells dna controls cellular activities by

If i add water to oil what will happen

If a molecule with a molecular formula of c13h18 is treated with an excess of h2 in the presence of finally divided pt metal under conditions required for maximum hydrogenation of the molecule to give a molecule with a formula c13h24, how many rings are in the molecule?