The great Rift Valley was formed by the separation of tectonic plates. What might this suggest about the boundaries between tectonic plates elsewhere on earth

This suggests that the boundraies elsewhere are either convergent, divergent, or transforming. When the plates crash into each other (Convergent) it creates things like volcanoes since the magma is escaping earth. When they're diverging, or going away from each other it forms a ridge, like the Rift Valley. Transforming boundries are when two boundries are sliding past each other which puts stress on the rock causing earthquakes.

d. the polar jet stream   lies between the polar easterlies and trade winds should be your answer