Please answer What are the 2 reasons that the seasons
change?

a) Earth's tilt and rotation
b) Earth's tilt and revolution
c) Earth's rotation and revolution
d) Earth's tilt and resolution

The answer is b, can you explain why it’s the answer please

NO LINKS 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? )

Development of new communities in disturbed environments, such as a burned or a clear cut forest, is called

The response is the basis for vaccination. primary secondary tertiary none of the above