Tell whether each of the following instances of $PCP$ has a solution. Each is presented as two lists $A$ and $B$, and the $i^{th}$ strings on the two lists correspond for each $i = 1,2,\cdot\cdot\cdot\cdot$
- $A=(01,001,10); \ B = (011,10,00).$
- $A=(01,001,10); \ B = (011,01,00).$
- $A=(ab,a,bc,c); \ B = (bc,ab,ca,a).$
