题目

某工业矿渣中主要含有Cu2O，还有少部分Al2O3、Fe2O3、SiO2 ， 从该矿渣中提取铜的操作流程如下：（已知：Cu2O+2H+═Cu+Cu2++H2O） （1） 固体混合物B与氢氧化钠溶液反应的化学方程式为．该反应物的一种重要用途为． （2） 滤液A中铁元素的存在形式只能为Fe2+ ， 理由是．涉及的离子方程式为（不必书写Cu2O与盐酸的反应）、．检验滤液A中Fe2+的试剂为． （3） 若将滤液C中的铝元素以沉淀形式析出，可选用的最佳试剂为（填序号）．A．氢氧Last summer, Maria and her mother moved from their house in the countryside to building in Chicago. Maria really liked some things about the city, but she missed her house and yard in the countryside. One day, Maria was in her flat building when she noticed her neighbor, Mrs. Garcia, carrying a gardening tool and a bag of soil. Maria wondered how Mrs. Garcia was able to garden in the city.“My mom used to grow the most delicious vegetables, and I know she misses her garden now that we don't have a yard,” said Maria.Mrs. Garcia laughed. “I’ll show you,” she said. Maria thought that Mrs. Garcia would take her to the park, but she took her to the roof (屋顸). When the door opened, Maria was surprised to see rows of flowers and vegetables on the roof.“What a wonderful garden! “ said Maria. Mrs. Garcia told Maria that for a long time the roof was just an empty space. Then some of the people in the building asked the owners to turn it into a community garden. The building owners liked the idea because the plants not only helped to keep the air clean, but they also helped to keep the building cooler during warmer weather.“I plant flowers in my own place,” Mrs. Garcia said, but you would be surprised by how different the plants are up here. Some people grow vegetables just like your mom. You can do some of the same things in the city as in the countryside. You just have to be creative ! "1.Which of the following is NOT the advantage of the community garden?A. It used the empty space well. B. It helped keep the air cleanC. It helped keep the building cooler. D. It made the building stronger2.After Maria visited the garden, she would most probably ask her mom to_______.A. go back to the countryside B. pick flowers from the gardenC. grow vegetables on the roof D. show her around the park3.What is the best title for this passage?A. A Creative Lady B. A Rooftop GardenC. An Empty Roof D. A Special Building