Yeah it uses some valuable scientific vocabulary and background knowledge, I hope this hypothesis will be good enough for your teacher (don't worry it will be)
Answer:
1) No shift
2) No shift
3) Leftward shift
4)Rightward sifht
Explanation:
1) 2) Adding N or Removing N in the equilibrium will produce No shift, because of its solid state, the N is not contemplated in the equilibrium equation:
3) Increasing the volume produces a decrase in the preassure due to the expansion of the gases. This will cause a leftward shift, because the system will try to increase the moles of gas and in consecuence of this, also increase the preassure.
4) Decreasing the volume has the opposite effect of the item 3): the preassure will increase and the system will consume moles of gas to decrease it, producing a rightward shift.