严重感染服用抗生素的同时应用糖皮质激素的目的是A．增强抗菌药物的抗菌活性 B．增强机

未经治疗的苯丙酮尿症患儿，智能发育落后的症状一般出现在生后（）。

A.1～2个月左右

B.3～6个月左右

C.6～7个月左右

D.8～10个月左右

E.10个月以上

在营销组合中，标准化程度最高的是促销策略。（）

轿车前窗电动刮水器处于自停位置时，刮片应处于与挡风玻璃（）边缘平行的位置，开机时，刮水器应立即向（）运动。

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.

一个灯泡上标有“220V100W”，则该灯泡额定电压的有效值为（）V。

A.220

B.311

C.180