Please help me with this please

Aneuron is stimulated with an electric pulse. the action potential is detected at a point 3.70 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? )

What environmental cues and landmarks do the geese use to determine the timing and direction of their migration over the mountains? how do they find their way?

14. which of the following codons code for threonine? a. ucg b. ugu c. cga d. aca