阅读下面这首唐诗，完成下面小题。

送虢州王录事之任

独孤及

谓子文章达，当年羽翼高。

一经俄白首，三命尚青袍。

未遇须藏器，安卑莫告劳。

盘根倘相值，试用发硎刀。

若函数$f\left(x\right)=\left|x+2a\right|-1$图象关于x=1对称，则实数a的值为（     ）

      阅读下文，回答问题。
                                                                                              七律·长征
                                                                                           红军不怕远征难，
                                                                                           万水千山只等闲。
                                                                                           五岭逶迤腾细浪，
                                                                                           乌蒙磅礴走泥丸。
                                                                                           金沙水拍云崖暖，
                                                                                           大渡桥横铁索寒。
                                                                                           更喜岷山千里雪，
                                                                                           三军过后尽开颜。