题目

选出与画线部分意思相同或相近的选项。 (1) The supermarket is close to my home. A . far B . not far C . near from D . not far from (2) We did a survey of our readers and this is what we learned. A . study B . studied C . know D . knew (3) He asked me to come in and sit down. A . take a seat B . be seat C . seat you D . take seat (4) What did you do that for? A . What B . When C . Why D . How某汽车配件厂新购进了一批黄铜(铜锌合金)。为了测定这批黄铜中铜的质量分数,化验人员将取来的样品先加工成粉末,然后利用该粉末与稀硫酸在烧杯内发生反应。在所进行的三次实验中,只有一次所取用的稀硫酸与黄铜样品是恰好完全反应的。有关实验数据记录如下: 请分析实验数据,完成下列问题:(1)黄铜样品与稀硫酸恰好完全反应时两种物质的质量之比为________________,该黄铜样品中铜的质量分数为_____________________。(2)计算黄铜样品与稀硫酸恰好完全反应后所得的溶液中溶质的质量分数。(计算结果精确到0.1%)
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