5.(5分)设函数f $\begin{array} { r } { \mathbf { \Pi } ( \mathbf { x } ) \mathbf { \Pi } = \left\{ \begin{array} { l l } { 1 + 1 \circ \mathbf { g } _ { 2 } \left( 2 - \mathbf { x } \right) , \quad \mathbf { x } < 1 } \\ { \quad } \\ { 2 ^ { \mathbf { x } - 1 } , \quad } \end{array} \right. } \end{array}$ ,则f $ \ ( \ - \ 2 ) \ + \mathbf { f } \ \left( \ \log _ { 2 } 1 2 \right) \ = \ ( $ )
Answer key
C