题目

（8分）利用生产钛白的副产品绿矾（FeSO4•7H2O）制备还原铁粉的步骤如下：将绿矾溶于稀硫酸溶液，向其中滴加(NH4)2CO3溶液，得到FeCO3•nH2O沉淀，静置，过滤，洗涤，干燥，再将FeCO3与煤粉一起焙烧，最终制得还原铁粉。涉及的主要反应有：FeCO3 FeO + CO2， C+CO 22CO， CO + FeOFe + CO2，Ks5u （1）检验绿矾是否已有部分氧化的方法是     ▲       。 （2）证明沉淀已经洗涤干净的方法是      ▲      。 （3）干燥过程中少量FeCO3•nH2O被氧化为FeOOH，反One great need in the lives of most people is change and variety（多样化），so holidays play an important part in our lives．We work hard during the year，so we feel tired and stressed（有力的）at times．We need holidays to relax，even if they only last for a few days This is especially true for women who，if they could get away from their husbands，children and family for even one week in the year，would feel much happier． Holidays have many good results．Firstly，they can improve the economy（经济）．If there were no holidays，people would have little time to spend the money they earn．Secondly，holidays allow people to relax after working hard throughout the year．During and after the holidays，people feel more relaxed and energetic；they then bring this energy to work when they continue working．Lastly，holidays help people learn how to enjoy life．Most people improve their relationships with their other family members during holidays． However，holidays also have bad aspects（方面）For example，many people said that they couldn’t enjoy shopping or travelling because there were so many people shopping and travelling，too．Anyway，most people realize that they need holidays．I can’t imagine what people’s lives would be like if there were no holidays． 1．People need holidays because ________． A．they need to spend money B．they need to rest after the hard work C．they want to make more friends D．they want to run away from the real life 2．Holidays are important，especially for ________ according to the passage． A．parents                   B．children                  C．women                  D．men 3．How many advantages do holidays have according to the passage? A．Two．                   B．Three．                  C．Four．                   D．Five． 4．Which of the following is NOT true? A．People can feel more relaxed after holidays． B．People will know how to enjoy life during holidays． C．The disadvantages of holidays are more than their advantages． D．People can have more energy to work after holidays． 5．What’s the writer’s attitude（态度）to holidays? A．There shouldn’t be more holidays． B．Holidays can bring some problems to us． C．Holidays are necessary． D．Holidays are not so important as money．