下列有关电路的说法正确的是（　　）

下列古诗文名句中，可以提醒我们正确对待困难的是（     ）  

已知30℃时，氯酸钾的溶解度是10克，现欲配制55克氯酸钾的饱和溶液，需用氯酸钾固体和水各多少克？

    In our city there are more and more cars and buses on the roads. Many people drive to work .First, it's good to have a car. You needn't to wait for the bus. You can go to work on time. Then ,there are many busy roads in the city . Can you drive safely? Traffic lights are very important. You must look at the traffic lights and wait for the green man. If someone is crossing the road, you must stop your car and look carefully. We must follow the rules and stay safe on the road.

①NaHCO₃溶液加水稀释，c（Na⁺）/c（HCO₃^﹣）的比值保持增大

②浓度均为0.1mol•L^﹣1的Na₂CO₃、NaHCO₃混合溶液：2c（Na⁺）=3c（CO₃^2﹣）+c（HCO₃^﹣）

③在0.1mol•L^﹣1氨水中滴加0．1mol•L^﹣1盐酸，恰好完全反应时溶液的pH=a，则由水电离产生的c（OH^﹣）=10^﹣amol•L﹣^﹣1

④向0.1mol/LNa₂SO₃溶液中加入少量NaOH固体，c（Na⁺）、c（SO₃^2﹣）均增大

⑤浓度相等的①NH₄HSO₄溶液、②NH₄HCO₃溶液、③NH₄Cl溶液中的c（NH₄⁺）：①＞②＞③

⑥NaHSO₃溶液显酸性，c（Na⁺）＞c（HSO₃^﹣）＞c（H⁺）＞c（OH^﹣）＞c（SO₃^2﹣）

⑦常温下，CH₃COONa和CH₃COOH混合溶液pH=7，c（Na⁺）=0.1mol•L^﹣1：c（Na⁺）=c（CH₃COO^﹣）＞c（CH₃COOH）＞c（H⁺）=c（OH^﹣）

⑧pH=3.6的0.1mol/L HX与0.1mol/L NaX的混合溶液中，c（H⁺）﹣c（OH^﹣）=c（X^﹣）﹣c（HX）