(1) Given the sets $A=\{1, b, a+b\}, B=\{a-b, a b\}$, and $A \cap B=$ $\{-1,0\}$, then the values of $a$ and $b$ are ( ).
(A) $-1,0$
(B) $0,-1$
(C) $-1,1$
(D) $1,-1$
(1) A Hint: Since $1 \notin A \cap B$, either $b$ or $a+b$ must be 0, and the other must be -1, but $a \neq 0$, otherwise set $A$ would have two identical elements, so it must be that $a=$ $-1, b=0$.