在电场的作用下，带正电的缓冲液整体向负极移动，称为（）。 A.保留时间 B.峰面积

凡在房产税征收范围内的具备房屋功能的地下建筑，包括与地上房屋相连的地下建筑以及完全建在地面以下的建筑、地下人防设施等，均应当依照有关规定征收房产税。（）

按下列要求填空：

①空气中含量最多的物质是（1）；

②常用于食品包装袋中的干燥剂是（2）；

③天然存在最硬的矿物质的化学式（3）；

④草木灰的主要成分是K₂CO₃，它属于化肥中的（4）肥，草木灰属于（5）（填“纯净物”或“混合物”）；

⑤镁带在二氧化碳中燃烧的化学方程式为：2Mg+CO₂C+2MgO，反应中的氧化剂是（6）．该反应中镁带中的镁元素转变为（7）（填“化合”或“游离”）态。

阅读理解。

     "I sat-in at a restaurant for six months, and when they finally agreed to serve me, they didn't have what I

wanted"-so went a famous line. In reality, the sit-in movement was not a joke. It began in Greensboro, North

Carolina, at 4:30 P. M., on the afternoon of February 1, 1960. On that day, Ezell Blair Jr., Joseph McNeil,

David Richmond, and Franklin McClain entered an F. W. Woolworth store. They sat down at a segregated (隔

离的) lunch counter, ordered coffee, and then refused to leave when told, 'We don't serve Negroes.'"

     The four young men had expected not to be served. What no one had expected, however, was that they

would sit there and politely, but firmly, refuse to leave. This was 1960, and throughout the South black people

were not allowed to sit at the same lunch counters with whites, swim at the same beaches, use the same water

fountains, or worship at the same churches. Segregation was the law, and it meant separation of the races in

every way.

     The next day, the four returned to Woolworth's-this time accompanied by sixteen other students. Again

they sat at the lunch counter and requested service. Again they were refused. And again, they declined to leave.

On Wednesday, February 3, seventy students filled the Woolworth's store. This time, the group included white

students as well as black. Many brought school books and studied while they waited. By this time, their protest

had become known nationwide as a "sit-in".

     On Thursday, there was trouble. An angry group of white teenagers began shoving (推搡) and cursing them

but were quickly removed by the police. By February 10, the sit-in movement had spread to five other states.

     By September 1961, more than 70,000 people, both black and white, had participated in sit-ins at segregated

restaurants and lunch counters, kneel-ins at segregated churches, read-ins at segregated libraries, and swim-ins

at segregated pools and beaches. Over 3,600 people had been arrested, and more than 100 students had been

driven away. But they were getting results. On June 10, 1964, the U. S Senate passed a major civil rights bill

outlawing (宣布为非法) racial discrimination in all public places. President Lyndon Johnson signed it on July 2,

and it became law. But the highest credit still goes to the four brave students from North Carolina who first

sat-in and waited it out.

1. In this passage, "sit-in" refers to _____. [ ]

A. an activity where people sit together and drink coffee freely

B. a bill which outlaws racial discrimination in all public places

C. a form in which people peacefully sit and decline to leave

D. a polite behavior that everyone enjoys

2. Which statement can be concluded from the fifth paragraph in the passage? [ ]

A. The sit-in movement was not successful.

B. The sit-in movement had a positive result.

C. Only black people participated in sit-ins.

D. A lot of protesters were arrested, with some students driven away from school

3. What was the purpose of the civil rights bill passed in 1964? [ ]

A. The highest credit went to the four brave students.

B. It declared that segregation was a law.

C. The students were allowed to participate in sit-ins.

D. It made racial segregation against the law in all public places.

4. What is the passage mainly about? [ ]

A. Segregation was the law in the South.

B. The first sit-in was in 1960.

C. The sit-ins helped to end segregation.

D. The civil rights bill was passed in 1964 by the U. S. Senate.

目前，湖北省文化系统管理的图书馆、博物馆、美术馆、文化馆（站）等文化设施的基本文化服务全部实行免费开放，服务人数逐年增长，服务水平不断提升。此举目的在于（）。

①发展公益性文化事业，保障人民基本文化权益

②全面提高公民道德素质，追求更高思想道德目标

③加强文化设施建设，提高公民科学文化修养

④加快发展文化产业，繁荣我国文化市场

A、①②

B、②④

C、①③

D、③④

为了保护工作人员、实验者及其周围的人群安全，动物实验从业单位应采取的有效措施包括：进行认真的（）。

A.医学监测

B.实验手段

C.防护设备

D.试验方案