如图所示，闭合线圈上方有一竖直放置的条形磁铁，当磁铁从图示位置向下运动时，线圈中

阅读理解。

    During the 1800s, African Americans worked long days in the fields of the American South. They sang

songs that they had brought from Africa while working. One person sang a line. Then a group of workers

repeated it. The song’s words told of the hardships(艰苦) that people suffered. They clapped their hands

and stomped(跺) their feet to the music.

    In the 1860s, the music changed greatly. African American music took new forms. It was also influenced by dance music, which had great rhythm(节奏). Banjos(班卓琴) became popular. A blues singer usually sang a line and then played the banjo in reply. By the early 1900s, the guitar had taken the place of the

banjo in the blues music.

    The blues music has many obvious characteristics. One of them is that the musical notes() are often “

bent”. That is, they are changed slightly to give a song more strength.

    Lyrics are the words of a song. Blues lyrics describe everyday life. The lyrics are often about the relationships between men and women. They tell about sadness and overwork. They tell about finding and losing

love, having money or being poor, being happy or sad and lonely. They almost always use the rhythms of

everyday speech. A group of blues lyrics usually has three lines. The second line repeats the first line. The

third line has different words.

    By the 1940s, large numbers of African Americans moved to Chicago.There, a new kind of "Chicago" blues began. The new music was excellent dance music. Chicago blues led to the birth of a new music

style －rock and roll.

1.This passage is mainly about _________.

A. the blues music                       

B. the life of African Americans

C. the blues lyrics                        

D. the rhythms of different music

2.What information does the passage NOT provide?

A.How the blues music developed as time went by.

B.What the blues lyrics are mostly about.

C.When African Americans moved to the American South.

D.How long the banjo was popular in the blues history.

3.Which of the following is the most likely taken from a blues song?

A.You have to help me. I’ll die if you don’t. You have to help me.

B.You have to help me. You have to help me. I’ll die if you don’t.

C.I’ll die if you don’t help me. You have to help me. You have to help me.

D.I’ll die if you don’t help me. You have to help me. Please help me.

4.What fact does the passage lead you to believe?

A.African Americans sang songs after a long day’s work to relax in the 1800s.

B.The blues singers in the 1860s usually played the guitar while singing songs.

C.It is not difficult to tell the blues music from others from its musical notes.

D.Rock and roll was the most popular blues music in Chicago in the 1950s.

“十一五”时期，党执政兴国的第一要务指()。

A．经济

B．发展

C．教育

D．科技

泵是（）元件，它的功能是将（）能转化为（）能。

某基金经理计划购买50万元面值的4年期的债券，其息票率为15%，从1年后开始每年支付一次。如果他将每年的利息按8%的年利率再投资，那么10年后他将拥有多少终值(保留10万位整数)

数据选择是（）。

A.将明显错误的数据剔除

B.将某些符合特定条件的数据筛选出来进行计算

C.将所谓“野值”数据排除在外

D.将要字符型数据转化为数字型数据

E.变量代换，构造新的变量