题目

   Lin Xiao, 21, a student at Guangdong University, has a big family – her two parents, a younger brother and two younger sisters. Lin took her role as the “big sister” seriously. When her first sister was born, Lin took turns with her mom holding the baby late into the night. “I almost did everything that was supposed to be a parent’s job, but I felt proud of myself,” she said. Not all of Lin’s classmates shared her experiences because of the family planning policy (政策), The one – child policy has been carried out in China for about forty years. But the situation 下列有关电化学的示意图中正确的是 [　　] A． B． C． D．