Just a tip on the first one. Even if you don't know the answer you can guess that its "x" because "z" and "y" are practically the same, and "w" is also the same just on the other side
For the second one the conventional current is flowing from left to right, and electrons flow against conventional current. So in this case the electrons are moving to the left. Now in a semiconductor the valence band is the outermost band whilst the electrons are at ground state. So when an electron jumps into the conduction band, it leaves a positive "hole" in the valence band. This causes the next to electron to jump to the left to fill in the hole, subsequently creating a new hole and so on. Therefore the electrons in the valence band are continuously moving to the left.