Piquette must have been seventeen then, although she looked about twenty. I stared at her, astounded that anyone could have changed so much.
句意：那时皮格特大概是十七岁，但看上去却有二十岁左右。我盯住她看，为一个人能发生这么巨 大的变化而大为惊讶。astounded感到震惊的。greatly surprised大吃一惊。worried担心的；困恼的。 frightened受惊的；害怕的。B选项与划线处意义最为接近，故选B。