临时用地的使用期限一般不得超过()年。A．5 B．4 C．3 D．2

具有________系统的________组织对________的反应称为炎症。

阅读理解。

     Everybody hates it, but everybody does it . A recent report said that 40% of Americans hate tipping .

    In America alone , tipping is a $16 billion-a-year industry .Consumers acting politely ought not to pay

more than they have to for a given service . Tips should not exist . So why do they ? The common opinion

in the past was that tips both rewarded the efforts of good service and reduced uncomfortable feelings of

inequality. And also, tipping makes for closer relations. It went without saying that the better the service,

the bigger the tip .

    But according to new research from Cornell University , tips no longer serves any useful function . The

paper analyzes numbers they got from 2547 groups dining at 20 different restaurants . The connection

between larger tips and better service was very weak . Only a tiny part of the size of the tip had anything

to do with the quality of service .

     Tipping is better explained by culture than by the money people spend . In America , the custom came

into being a long time ago . It is regarded as part of the accepted cost of a service. In New York

restaurants , failing to tip at least 15% could well mean dissatisfaction from the customers . Hairdressers

can expect to get 15%-20% , and the man who delivers your fast food $ 2. In Europe , tipping is less

common . In many restaurants the amount of tip is decided by a standard service charge . In many Asian

countries , tipping has never really caught on at all . Only a few have really taken to tipping.

    According to Michael Lynn , the Cornell papers' author , countries in which people are more social or

outgoing tend to tip more . Tipping may reduce anxiety about being served by strangers . And , says ,

Mr . Lynn, "in America , where people are expressive and eager to mix up with others , tipping is about

social approval . If you tip badly , people think less of you . "Tipping well is a chance to show off ."

1. This passage is mainly about ______.

A. different kinds of tipping in different countries

B. the relationship between tipping and custom

C. the original and present meaning of tipping

D. most American people hate tipping

2. Which of the following best explains the underlined phrase "caught on" ?

A. been hated  

B. become popular  

C. been stopped  

D. been permitted

3. Among the following situations , in your opinion , who is likely to tip most ?

A.A Frenchman just quarreled with the barber who did his hair badly in NY.

B. A Chinese student enjoyed his meal in a famous fast food restaurant in NY.

C. A Japanese businessman asked for a pizza delivery from a Pizza Hut in NY.

D. An American just had a wonderful dinner in a well-known restaurant in NY.

4. We can infer from this passage that  _______.

A. tipping is no longer a good way to satisfy some customers themselves

B. tipping has something to do with people's character

C. tipping in America can make service better now

D. tipping is especially popular in New York

燃油系统由哪些设备组成？其各自作用是什么？

颈椎病颌枕吊带牵引下列错误的是

A．可解除肌痉挛

B．适用于除交感神经型外的各型颈椎病

C．牵引重量为2～6kg

D．牵引时头前屈15度

E．可使小关节内的滑膜皱襞复位

有关 * * 下裂，下列哪项不正确（）

A.属常染色体显性遗传

B.与妊娠期间应用雌激素与孕激素无关

C.常合并隐睾

D.常合并腹股沟斜疝

E.严重时易产生性别混淆