Answer from cs61c-ck (Allen Lee 16583554) for Question 1
L1 cache and TLB are both "caches" but L1 cache is a cache for the data in memory, whereas the TLB is a cache on the page table mappings.  Even though L1 cache is much, much bigger, we have a high miss rate because we might be accessing anything located anywhere in data memory.  The TLB is different because it's simply a buffer that holds virtual page address to physical page address translations; and any particular page in memory can hold anywhere from 4kb to 64kb, so we cover a lot of data.  L1 cache blocks, on the other hand, often only contain 4 to 16 bytes.