[填空题]
A neuron is stimulated with an electric pulseij; *3pf b6e9xh3rhw t. The action pox ;t5 n8f k/qjo5egs5otential is detected at a point 3.40 cm down the axon 0.0052 s later. When the action potential is detected 7.20 cm from the point of stimulation, the time required is 0.0063 s. What is the speed of the electric pulse along the axon? (Why are two measurements needed instead of only one?j ots 5k /;e5qongxf58) m/s
