Answer from cs61c-cg (Daniel Lau 16776873) for Question 2
In C, they have statements like while, do while, for, if, switch. MIPS has only loop, if and switch.

Because MIPS is a low level language, we want the instructions to be as simple as possible. Hence something like while and for, which is the same as loop but with different syntax, is eliminated from the MIPS list.