题目

阅读理解。阅读下面短文,并做短文后面的题目,从四个选项中,选出能回答所提问题或完成所给句子的最佳答案。         Do you know how to write an English letter? When we write a letter in Chinese, we always put the date at the end of the letter. But it is different in English. We have to put it on the top of the right corner. And above the date, we also write the number of our house and the names of our street, city and country. To begin the letter, we always use words like “Dear sir” “Dear Mr/ Miss/ Mrs …” To the end of the letter,19．某同学欲配制85ml0.3mol/LCuSO4溶液．（1）本实验所需容量瓶的规格为100ml；应称取胆矾晶体（CuSO4•5H2O）的质量为7.5g．（2）下列操作中，容量瓶所不具备的功能有A．配制一定体枳准确浓度的溶液B．长期贮存溶液C．用來加热溶解固体溶质D．量取一定体积的液体（3）在配置过程中，该同学已经有天平（带砝码）、药匙、100ml容量瓶、玻璃棒，要完成该实验还缺少的仪器是烧杯、胶头滴管．（4）在配制CuSO4溶液实验中，由于操作不当，会引起误差，下列情况会使所配溶液浓度偏低的是BEA．定容时俯视刻度线b．称量固体时将砝码放置在托盘天平左盘C．胆矾己失去部分结晶水D．转移溶液前容量瓶内有少量蒸馏水E．定容后摇勾，发现液面降低，又补加少量水至刻度线．