An impulse moves from one neuron to another through the action of:

it has one origin of replication, but it proceeds in two directions - d)

a axis of a graph is a color or shade so we can all go outside and have a party so we can eat   some grilled cheese sammiches and broccoli and have some ugly fun times

i don't know why i put this, i know its not the i was just bored : p

delete this answer while you can