问题 单项选择题

列关于低温诱导染色体加倍实验的叙述,正确的是()

A.原理:低温抑制染色体着丝点分裂,使子染色体不能分别移向两极

B.解离:盐酸酒精混合液和卡诺氏液都可以使洋葱根尖解离

C.染色:龙胆紫溶液和醋酸洋红溶液都可以使染色体着色

D.观察:显微镜下可以看到大多数细胞的染色体数目发生改变

答案

参考答案:C

阅读理解

Everywhere you look, large quantities of information in the world are pouring. This data flood is already starting to transform business, government, science and everyday life. It has great potential for good — as long as consumers, companies and governments make the right choices about when to restrict the flow of data, and when to encourage it.

A few industries have led the way in their ability to gather and take advantage of the data. Credit-card companies monitor every purchase and can identify cheats with a high degree of accuracy. Stolen credit cards are more likely to be used to buy hard liquor than wine, for example, because it is easier to overlook. Insurance firms are also good at combining clues to spot doubtful claims: dishonest claims are more likely to be made on a Monday than a Tuesday, since policyholders (保险客户) who stage accidents tend to assemble friends as false witnesses over the weekend. By combining many such rules, it is possible to work out which cards are likeliest to have been stolen, and which claims are untrue. By analyzing “basket data”, supermarkets can make promotions to appeal to particular customers’ preferences. The oil industry uses supercomputers to help them before drilling wells.

But the data flood also poses risks. There are many examples of databases being stolen: disks full of social-security data go missing, laptops loaded with tax records are left in taxis, credit-card numbers are stolen by online purchase. The result can be privacy made public, identity stolen and cheats permitted large space. Rather than owning and controlling their own personal data, they very often find that they have lost control of it.

The best way to deal with the data flood is to make more data available in the right way, by requiring greater transparency in several areas. First, users should be given greater access to and control over the information held about them, including whom it is shared with. Google allows users to see what information it holds about them, and lets them delete their search histories or modify the targeting of advertising, for example. Second, organizations should be required to disclose details of security breaches, as is already the case in some parts of the world, to encourage bosses to take information security more seriously. Third, organizations should be subject to an annual security check, with the resulting grade made public (though details of any problems exposed would not be). This would encourage companies to keep their security measures up to date.

59. What is the best title for this passage?

A. Information Flood             B. Benefits of Data Flood

C. Harms of Data Flood           D. How to Use Data in a Right Way

60. From the passage we can infer that ________.

A. lots of data are lost because of hardware problems

B. online purchases are becoming more and more popular

C. credit cards are not so secure to use and will go out of use very soon

D. insurance firms have to investigate before they confirm their policyholders’ claims

61. Which of the following is the writer’s opinion about how to deal with the data flood?

A. Personal information should be used for public benefits.

B. The users should be given the right to access public information.

C. Companies should update their measures to guarantee their data safety.

D. Organizations should keep their resulting grade of security checks unknown to the public.

62. From the passage we can conclude that _________.

A. the data flood makes peoples’ life less convenient and more expensive

B. companies and insurance firms are responsible for the data flood

C. the information flood is more useful to organizations than to individuals

D. the information flood has both positive and negative influence on modern life

单项选择题