Answer from cs61c-ej (Leon Wang 16247444) for Question 3
I do not completely understand the last example.  

"Assume that four sequential words in memory, starting at an address contained in $t4, have addresses corresponding to the labels L0, L1, L2, and L3."

Then in the code below, "jr $t0" is supposed make the execution jump to L0, L1, L2, L3 but I don't see how $t0 can be associated to L0-L3 by the user.