如图, $A B C-A^{\prime} B^{\prime} C^{\prime}$ 是体积为 1 的棱柱, 则四棱雉 $C-A A^{\prime} B^{\prime} B$ 的体积是 ( )

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$\because V_{C-A^{\prime}} B^{\prime} C^{\prime}=\frac{1}{3} V_{A B C-A^{\prime}} B^{\prime} C^{\prime}=\frac{1}{3}$,
$\therefore V_{C-A A^{\prime} B^{\prime}}{ }^{B}=1-\frac{1}{3}=\frac{2}{3}$.