问题 选择题

下列图示实验所得出的结论中,不正确的是  (    )

A.氧气约占空气体积的1/5

B.二氧化碳的密度比空气大且不支持燃烧

C.天平不平衡说明该反应不遵守质量守恒定律

D.燃烧条件之一是温度需达到可燃物的着火点

答案

答案:C

题目分析:C中天平不平衡是由于生成的二氧化碳逸散到了空气中,依然遵守质量守恒定律,C错误。故选C。

阅读理解

阅读理解。

     The iPhone, the iPad, the iPod: each of Apple's products sounds cool and has become a fad (一时

的风尚). Apple has cleverly taken advantage of the power of the letter "i"-and many other brands are

following suit. (仿效) The BBC's I Player-which allows Web users to watch TV programs on the

Internet-adopted the title in 2008. A lovely bear-popular in the US and UK-that plays music and video is

called "I Teddy". A slimmed- down version of London's Independent newspaper was launched last week under the name "i".

     In general, single-letter prefixes (前缀) have been popular since the 1990s, when terms such as e-mail and e-commerce first came into use.

     Most "i" products are targeted at young people and considering the major readers of Independent's"i", it's no surprise that they've selected this fashionable name.

     But it's hard to see what's so special about the letter "i". Why not use "a", "b",or "c" instead? According

to Tony Thorne, head of the Language Center at King's College, London, "i" works because its meaning

has become ambiguous. When Apple uses "i", no one knows whether it means Internet, information,

individual or interactive, Thorne told BBC Magazines. "Even when Apple created the iPod, it seems it

didn't have one clear definition,"he says.

     "However, thanks to Apple, the term is now associated with portability (轻便),"adds Thorne.

     Clearly the letter "i" also agrees with the idea that the Western World is centered on the individual.

Each person believes they have their own needs, and we love personalized products for this reason.

     Along with "Google" and "blog", readers of BBC Magazines voted "i" as one of the top 20 words that

have come to define the last decade.

     But as history shows, people grow tired of fads. From the 1900s to 1990s, products with"2000"in

their names became fashionable as the year was associated with all things advanced and modern.

However,

as we entered the new century, the trend disappeared.

1.We can infer that the Independent's "i" is aimed at         .

A. young readers      

B. old readers    

C. fashionable women    

D. engineers

2.The underlined word "ambiguous" means"         ".

A. popular          

B. uncertain      

C. definite            

D. fashionable

3. Nowadays, the "i" term often reminds people of the products which are        .

A. portable                          

B. environmentally friendly

C. advanced                          

D. recyclable

4. The writer suggests that           .

A. "i" products are often of a high quality

B. the popularity of "i" products may not last long

C. the  letter "b" replaces letter "i" to name the products

D. I Teddy is a live bear

单项选择题 案例分析题