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问题 选择题

下列有关说法正确的是

A．对于反应2SO2(g)+O2(g)2SO3(g)，压缩气体体积使压强增大（其他条件不变），则SO2的转化率增大，平衡常数K也增大

B．电解法精炼铜时，精铜作阳极，粗铜作阴极

C．在硫酸钡悬浊液中加入足量饱和Na2CO3溶液处理，向所得沉淀中加入盐酸有气体产生，说明Ksp(BaSO4)>Ksp(BaCO3)

D．CH3COOH溶液加水稀释后，电离程度增大，溶液中的值不变

答案

答案：D

题目分析：A、压缩气体体积使压强增大，平衡向气体系数减小的方向移动，即向正反应方向移动，SO2的转化率增大，但平衡常数不变，错误；B、电解法精炼铜时，粗铜作阳极，精铜作阴极，错误；C、在硫酸钡悬浊液中加入足量饱和Na2CO3溶液，向所得沉淀中加入盐酸有气体产生，BaSO4沉淀转化为BaCO3沉淀，因为饱和Na2CO3溶液中CO32‾浓度大，硫酸钡悬浊液中SO42‾浓度很小，所以无法判断Ksp(BaSO4)与Ksp(BaCO3)的大小，错误；D、CH3COOH溶液加水稀释后，电离程度增大，等于Ka/Kw，值不变，正确。

填空题

在DOS环境下，代表键盘和显示器的设备文件名为　【２】　。
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单项选择题

A businessman must keep records of the money he takes in and the money he spends. The work of keeping such records is called bookkeeping. The work of deciding how the records should be set up is called accounting. An accountant also finds out, by studying the records, whether or not a business is doing well. The accountant must know many things about the business.

Suppose a man owns a small clothing store, he keeps records that show that he spent money for newspaper advertising and for suits, shirts, shoes, and neckties to sell to his customers. He had to pay a young man to help him in the store. He also paid rent and had other expenses.

At the end of the year, he must take an inventory. That is, he counts how many pieces of clothing he has on hand. Then he must find out exactly how many he sold, how much money he took in, and how much money he spent in running the business. If he took in more than he spent, he made a profit for the year. If he spent more than he took in, he suffered a loss. He depends on his store accounting records to get all this information.The owner of a small clothing store can keep records without much trouble. But a big oil company or a big bank has many difficult accounting problems. The company must know how much money is to be paid by its debtors and how much it owes other companies for supplies. It must know how much it has lost in depreciation, or wear and tear of its equipment. All of this information must be kept in the company’s accounts. Big companies employ many accountants.After a company’s accountants finish their yearly count, their work must be officially examined. Experts from outside company double-check the records to be sure the accounts are correct.

After taking an inventory, if the owner found that he had got more money than he had spent, he made（）

A. a profit

B. a loss

C. an income

D. an interest
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