病例对照研究试验结果属于（） A.一级证据 B.二级证据 C.三级证据 D.四级证据

脓胸多见致病菌（）。

A.肺炎球菌

B.肺炎球菌和大肠杆菌

C.金葡菌和厌氧菌

D.链球菌和金葡菌

E.金葡菌和大肠杆菌

阅读理解。

     Each year about a quarter of a million Americans study abroad. For many of them, a summer or a

semester in a foreign country now involves more than just sitting in classrooms and hanging out with other American students. Instead, they are encouraged and sometimes required to be involved in the local

communities they are studying in.

     "It's absolutely important that they know something about how people in other parts of the world live

and think, and how they behave," says William Finlay, head of the sociology department at the University

of Georgia. In 2008, he co-founded a study abroad program with South Africa's Stellenbosch University.

It combines traditional academic in-class learning with community involvement.

     "We've been working with a non-government organization in the township. Our students typically

either work with little children in day care centers or work in the library and teach very basic computer

skills to young children," says Finlay.

     The three-week program proved to be an unforgettable experience for Hillary Kinsey. She says, "It

was interesting to learn the history of the area and then talk to these people and see what the social

dynamics were, and how certain groups felt about other groups."

     When Hillary Kinsey returned home from South Africa, she and other students in the program

established a non-profit group. Kinsey says the group wants to contribute to advancing education and

development in South Africa. "One of the purposes of the group is that we hope to raise money and

awareness about the situation where those people live and help to promote any sort of educational

development that we can, " Kinsey added.

     While many study abroad programs focus on helping Americans to learn foreign languages, others

take a more intensive approach. "In all of our locations, we place students with local roommates," says

Mark Lenhart, director of CEF Academic Programs, which sends more than a thousand students to China, Korea and other countries each year.

     He says American students benefit from such one-on-one interactions, in spite of the challenges they

face. Lenhart says, "They have to adjust to the local life. This will enable students to become more employable when they graduate."

1. What is the main idea of this passage?

A. How non-profit groups work in South Africa.

B. How to take part in study abroad programs.

C. Americans studying abroad pay more attention to working with local children.

D. Americans combine community involvement with study while studying abroad.

2. The purposes of Hillary Kinsey's non-profit group include all of the following, EXCEPT           .

A. learning more about South Africa

B. raising money for local people  

C. helping to develop education in South Africa  

D. raising people's awareness of the local situation

3. Which of the following CANNOT be used to describe Hillary Kinsey's feelings about studying abroad?

A. Interested.  

B. Surprised.  

C. Impressed.  

D. Unforgettable.

4. The advantages of studying abroad mentioned in this passage include           .

① making more friends

② being qualified for more jobs

③ learning a foreign language

④ having the ability to adjust to a new environment

A. ①②③        

B. ②③④          

C. ①③④        

D. ①②④

运行中的进程可以处于______、就绪、等待3种状态之一。

以下语句中存在语法错误的是______。

A) char ss[6][20]；ss[1]="right"； B) char ss[][20]="right"；
C) char*ss[6]；ss[1]="right"；
D) char*ss[]="right"；

韦伯