翻译下列句子。

    Ann is my classmate. She comes from New York, and she lives in Shanghai with her parents now. Every morning, she goes to KFC to have breakfast. Sometimes she buys a hamburger for me. She can't speak Chinese well. In the evening, her father often helps her with it. He's a teacher in our school. He can speak Chinese very well.

    Ann thinks the school life(生活)in China is very interesting. Ann likes reading Chinese books because she wants to know more about China. She tries(努力)to talk with her Chinese friends in Chinese. She hopes to speak Chinese well. She is very happy to live in China. She loves people here.

①如澄清石灰水，它的有效成分为氢氧化钙，写出其中的氢氧根离子____．（填离子符号）

②处的物质类别是____．

③如氢气，保持氢气化学性质的最小粒子是____．（填粒子名称）

④如氧化铝，请写出氧化铝的化学式____．