已知集合 $A=\{-1,0,1,2\}, B=\left\{x \mid x^{2} \leq 1\right\}$, 则 $A \cap B=（ ）$
 $\because x^{2} \leq 1, \therefore-1 \leq x \leq 1, \therefore B=\{x \mid-1 \leq x \leq 1\}$,又 $A=\{-1,0,1,2\}, \therefore A \cap B=\{-1,0,1\}$. 故选 A.

## 【名师点睛】本题考查了集合交集的求法, 是基础题.