画出图中入射光线AO的反射光线,并标出反射角的大小.

汽车、电动车一般使用铅蓄电池．某铅蓄电池使用的酸溶液是质量分数为20%的稀硫酸．请回答下列有关问题：

一种海水电池的反应原理可表示为：5MnO₂＋2Ag＋2NaCl＝Na₂Mn₅O₁₀＋2AgCl，有关该反应的说法正确的是（   ）

    Mr Black was walking in the forest（森林） He was scared when he heard a terrible noise. But he could not get out of the forest. His friends were waiting for him in a village outside the forest. They would give him a lot of money if he took a tiger to them, or they were going to laugh at him.
    Mr Black liked hunting(打猎). He usually killed some birds and animals. But a week ago, after he drank too much, he called himself a brave hunter. So his friends bet(打赌) him twenty thousand dollars if he could kill a tiger.
    Suddenly, he heard a little noise. He ran to a big tree,and climbed up it quickly.He didn't come down until he saw it was a farmer. He went close to him and asked, “Excuse me, sir.Are there any tigers in the forest?”
    “Yes,” said the farmer. “I saw a lot of tigers' tracks（足迹）about a kilometer north near here.”
“Good!”Mr Black said in a hurry. “Which way is to the south,then?”

1913年，某身着日式服装的革命党人途遇一老农，老农询问其国籍，某称“予中华民国人也”。老农“忽做惊状，似绝不解中华民国为何物者”，当被告知亦为中华民国人时，老农茫然惶然，连声说：“我非革命党，我非中华民国人。”这表明