问题 单项选择题

下述关于数据库系统的叙述中正确的是______。

A.数据库系统减少了数据冗余

B.数据库系统避免了一切冗余

C.数据库系统中数据的一致性是指数据类型的一致

D.数据库系统比文件系统能管理更多的数据

答案

参考答案:A

解析:[知识点] 数据库的基本概念:数据库,数据库管理系统,数据库系统[评析] 由于数据的集成性使得数据可为多个应用所共享,特别是在网络发达的今天,数据库与网络的结合扩大了数据关系的应用范围。数据的共享自身又可极大地减少数据冗余性,不仅减少了不必要的存储空间,更为重要的是可以避免数据的不一致性。所谓数据的一致性是指在系统中同一数据的不同出现应保持相同的值,而数据的不一致性指的是同一个数据在系统的不同拷贝处有不同的值。

阅读理解

The United Nations says forty million people or so around the world went hungry in 2008, mainly because of higher food prices. Early estimates from the UN Food and Agriculture Organization (FAO) show that 963 million people did not get enough to eat.

World food prices have dropped since early 2008. Prices of major crops have decreased by more than half from their height earlier last year. But they remain high compared to earlier years.

But FAO official Hafez Ghanem says lower prices have failed to end the food crisis (危机) in many poor countries. “For millions in developing countries,” he says, “getting enough food every day to live an active and healthy life is a distant dream. ”

The FAO says food shortage is a threat to people's health. Today, two-thirds of the world's undernourished people live in just a few countries. These are India, the Democratic Republic of Congo, Bangladesh, Indonesia, Pakistan, Ethiopia and so on.

A report on food insecurity warns that the current economic crisis could send even more people into hunger and poverty.

In sub-Saharan Africa, the percentage of the people who continually go hungry fell from 34% in 1997 to 30% in 2008. But the FAO says Ghana is the only country that has reached two sets of hunger reduction targets. These were set by the 1996 World Food Summit and the Millennium Development Goals. The main reason is the growth in agricultural production in Ghana.

The FAO says some countries in Southeast Asia like Thailand and Vietnam have made progress in hunger reduction goals. But South Asia and Central Asia haven't, and North Korea is still in hot water.

小题1:What FAO official Hafez Ghanem says implies(暗示)__________

A.it's easy but takes long to provide people with enough food

B.enough food can make people more active and healthier

C.there is difficulty solving the food shortage in a short time

D.people in developing countries will never get enough food小题2:The underlined word "undernourished" in Para. 4 probably means ________.

A.hungry and unhappy

B.unhealthy for lack of food

C.not fat because of poverty

D.undeveloped and poor小题3:What is the best title of this passage?

A.The food production of the world

B.The hunger reduction target of the FAO

C.The food shortage around the world

D.The solution to the global food shortage

单项选择题 A1/A2型题