A:气体X为O2
B:c电极为负极,发生的电极反应式为H2﹣2e﹣=2H+
C:一段时间后A处pH降低
D:当有0.4mol电子转移时,在B极上生成标准状况下气体2.24L
Nanjing, the ancient capital of the six dynasties, is becoming ________ international city and attracts more and more foreign tourists every year.