. ____ by the thought that she was suffering a heart attack, she screamed for help. A. Terrifying B. Terrified C. Being terrified D. Having terrified 答案:B氢—氧燃料电池是将H2和O2分别通入电池,穿过浸入20%~40%的KOH溶液的多孔碳电极,其电极反应式为:2H2+4OH--4e-===4H2O和O2+2H2O+4e-===4OH- 。则下列叙述正确的是:
A. 通H2的一极是正极,通O2的一极是负极?
B. 通O2的一极是正极,通H2的一极是负极
C. 工作一段时间后电解质溶液pH增大?
D. 工作时正极区附近pH减小?