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问题 选择题

化学与环境、材料和科技等密切相关。下列说法中错误的是（   ）

A．积极推行“限塑令”，加快研发利用二氧化碳合成的聚碳酸酯类可降解塑料

B．光导纤维在信息产业中有广泛应用，制造光导纤维的主要材料是单质硅

C．即将到来的新能源时代，核能、太阳能和氢能等很可能成为主要能源

D．2011年11月3号1时43分神州八号与“天宫一号”完成了首次对接，神八在制造过程中使用了大量的复合材料

答案

答案：B

答案:B

B．不正确，制造光导纤维的主要材料是二氧化硅

A、防止白色污染；C、寻找开发新能源对于解决当今世界严重的环境污染问题和资源（特别是化石能源）枯竭问题具有重要意义。D、复合材料，是以一种材料为基体，另一种材料为增强体组合而成的材料。各种材料在性能上互相取长补短，产生协同效应，使复合材料的综合性能优于原组成材料而满足各种不同的要求。神八在制造过程中使用了大量的复合材料，以满足太空生存所需的各种要求。

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.

A small store owner can usually keep records（）

A. with difficulty

B. easily

C. without any help

D. without working
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选择题

下列反射活动属于条件反射的是[ ]

A．狗吃到肉，分泌唾液      

B．青梅入口，分泌唾液

C．看见糖果，分泌唾液      

D．强光射眼，迅速闭眼
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