题目

阅读下列短文，从每题所给的四个选项(A、B、C和D)中，选出最佳选项。A I am a taxi driver. One Monday morning, I had stopped at New York Hospital when I found a well-dressed man coming over. He was waving to me. I waited until he jumped into the cab. “La Guardia Airport, please,” he said. As always, I wondered about my passenger. “What do you do?” “I am working at the hospital.” For some unknown reason, I decided to ask for his help. “Could I ask a favor of you?” He didn’t answer. “I have a son, 16. He's doing well in school. He wants a job this su17．用氢氧化钾溶液作电解质溶液，写出氢氧燃料电池的电极反应正极：O2+2H2O+4e-=4OH-，负极：2H2+4OH--4e-═4H2O，该电池总反应的方程式为O2+2H2=2H2O．