(1)①在淀粉碘化钾溶液中,滴加少量次氯酸钠碱性溶液,立即会看到溶液变蓝色,这是

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问题:

(1)①在淀粉碘化钾溶液中,滴加少量次氯酸钠碱性溶液,立即会看到溶液变蓝色,这是因为________,离子方程式__________________________。

②在碘和淀粉形成的蓝色溶液中,滴加亚硫酸钠碱性溶液,发现蓝色逐渐消失,这是因为________________________。离子方程式是_______________________。

③对比①和②实验所得的结果,将I2、ClO、SO42按氧化性由强到弱的顺序排列为________________________________________。

(2)今有铁片、铜片,设计实验证明以下事实,并写出反应的化学方程式。

①浓硫酸的氧化性比稀硫酸强。___________________________。

②氯化铁溶液中Fe3的氧化性比硫酸铜溶液中的Cu2强。__________________________________________。

③铁的还原性比铜强。_________________________。

考点:离子方程式
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金融风险是由于各种( )因素的影响而发生损失的可能性。

A.确定性

B.不确定性

C.稳定性

D.不稳定性

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配股中未被认购并且承销商未予包销的股份,根据中国证监会的有关规定,及时在可配股总数中予以扣除,并予以登记。( )

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我国的会计年度采用公历制,与我国的计划财政年度保持一致。()

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D        

"In only six days I lost seven pounds of weight. "

"Two full inches in the first three days!"

These are the kinds of statements used in magazine, newspaper, radio and television ads, promising new shapes and new looks to those who buy the medicine or the device. The promoters of products say they can shape the legs, slim the face, smooth wrinkles, or in some other way to add to beauty or desirability.

Often such products are nothing more than money-making things for their promoters. The results they produce are questionable and some are dangerous to health.

To understand how these products can be legally promoted to the public, it is necessary to understand something of the laws covering their regulation. If the product is a drug, FDA(Food and Drug Administration )can require proof (证明) under the Food, Drug, and Cosmetic Act that is safe and effective before it is put on the market. But if the product is a device, FDA has no authority to require premarketing proof of safety or effectiveness. If a product already on the market is a danger to health. FDA can request the producer or distributor to remove it from the market voluntarily, or it can take legal action, including seizure (查封) of the product.

One notable case a few years ago involved an electrical device called the Relaxacisor, which had been sold for reducing the waistline. The Relaxacisor produced electrical shocks to the body through contact pads. FDA took legal action against the distributor to stop the sale of the device on the grounds that it was dangerous to health and life.

Obviously, most of the devices on the market have never been the subject of court proceedings (法律诉讼),and new devices appear continually. Before buying, it is up to the consumer to judge the safety or effectiveness of such items.

71. It can be inferred that the ads mentioned in the text are        .

A. objective    B. costly    C. unreliable    D. illegal

72. Which of the following is true according to the text?

A. The court is in charge of removing dangerous products.

B. New products are more likely to be questionable.

C. The production of a device must be approved by FDA.

D. The promoters usually just care about profits.

73. FDA can ask for the proof of safety and effectiveness of a product        .

A. if it is a drug      

B. if it is a device

C. if its consumers make complaints

D. if its distributors challenge FDA's authority

74. The Relaxacisor is mentioned as        .

A. a product which was designed to produce electricity

B. a product whose distributor was involved in a legal case

C. a successful advertisement of a beauty product

D. an example of a quality beauty product

75. The author intends to        .

A. make consumers aware of the promoters' false promises

B. show the weakness of the law on product safety

C. give advice on how to keep young and beautiful

D. introduce the organization of FDA

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染色体倒位的细胞学效应与遗传学效应是什么有何应用

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