为测定某地石灰石样品中碳酸钙的质量分数，进行以下实验；向装有_爱下问搜题

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问题计算题

为测定某地石灰石样品中碳酸钙的质量分数，进行以下实验；向装有10.0g石灰石样品的烧杯中，加入47.2g稀盐酸，恰好完全反应，烧杯中剩余物质的总质量随时间变化关系如下表：（石灰石中的杂质不参加反应且难溶于水）

求：

（1）最终生成二氧化碳的质量为________ g；

（2）样品中碳酸钙的质量分数；

（3）将反应后烧杯中的剩余物质进行过滤，再向滤液中加入多少克水可以得到5%的氯化钙溶液？

答案

（1）2.2；

（2）样品中CaCO₃的质量分数为50%；

（3）所需加水的质量为61g．

完形填空

Three engineers(工程师) and three accountants (会计) were traveling by train to a meeting. At the station, the three accountants each bought a ticket, but the three engineers bought only a single ticket. “How are three people going to travel    36   only one ticket?” asked an accountant. “Watch and you’ll see,” answered an engineer.
They all    37  the train. The accountants took their own    38  , and all the three engineers went into a restroom and   39   the door behind them. The train    40  the station, and after a while the conductor (售票员) came to    41   tickets. He knocked on the restroom door and said, “Ticket, please!” The door opened just a    42   and a single arm appeared with a ticket in hand. The conductor    43   it and moved on.
The accountants saw this and    44   it was quite a clever idea.    45   after the conference, the accountants decided to    46   what the engineers did on the return trip and   47   some money.
When they got to the station, they bought a single ticket for the return trip. To their 48   , the engineers bought no tickets    49  .
“How are you going to travel without a ticket?” asked one    50   accountant. “Watch and you’ll see,” answered an engineer.    51   they got on the train the three accountants went into a restroom and the three engineers went into another one that was   52  . Then the train started. Shortly afterwards(不久之后), one of the engineers left his restroom and walked    53  to the restroom   54   the accountants were    55 . He knocked on the door and said, “Ticket, please!”

D．not closely

多项选择题

下列支出中，不允许个体工商户所得税前列支的项目包括( )。

A．缴纳的房产税

B．缴纳的个人所得税

C．赔偿金、违约金支出

D．对外投资支出

E．各种赞助支出