Which of the following statements characterizes an excitatory neuron? . -it sends an impulse back to the cell body of a neuron.

-it carry an impulse to the next neuron.

-it stops the passage of an impulse at a neuron.

multiple allele inheritance is traits controlled by more than 2 alleles (ex: pigeons having 3 alleles of one gene govern their feather color).   so the answer is a.

a=c and then d= c because of the band so you get ac/dc and you add them together you get sound waves