下图为世界四个地点的坐标， 作为大洲分界线的经线经过的地点是 ( ) A．A

(B)

Martin Luther King, Jr., is well known for his work in civil rights and for his many famous speeches, among them his moving “I Have a Dream” speech. But few people know much about King’s childhood, Martin Luther as he was called was born in 1929, in Atlanta, Georgia, at the home of his maternal grandfather. Martin Luther’s grandfather, the Reverend A.D. Williams, purchased their home on Auburn Avenue in 1909, 28 years before Martin Luther was born. The Reverend A.D. Williams, an eloquent speaker, played an important role in the community because so many people’s lives centered around the church. He allowed his church and his home to be used as a meeting place for a number of organizations dedicated to the education and social advancement of blacks. Martin Luther grew up in this atmosphere, with his home being used as community gathering place, and was no doubt influenced by it.

Martin Luther’s childhood was not especially memorable. His father was a minister and his mother was a musician. He was the second of three children, and he attended all-black schools in a black neighbourhood. The neighbourhood was not poor, however, Auburn Avenue was the main artery through a prosperous neighbourhood that he had come to symbolize achievement for Atlanta’s black people. It was area of banks, insurance companies, builders, jewelers, tailors, doctors, lawyers and other black-owned or black-operated businesses and services. Even in the face of Atlanta’s segregation (种族隔离), district thrived. Dr. King never forgot the community spirit he had known as a child, nor did he forget the racial prejudice（歧视） that was a seemingly insurmountable barrier that kept black Atlantans from mingling with whites.

68. This passage mainly gives an account of ______.

A. the prejudice that existed in Atlanta  B. Martin Luther’s grandfather

C. Martin Luther King’s childhood              D. the neighbourhood where King grew up

69. According to the author, King was influenced by ______.

A. community spirit                           B. black lawyer     

C. his mother                                     D. his grandfather’s speeches

70. The word “mingling” in paragraph 2 is the closest in meaning to ______.

A. interfering         B. consuming         C. associating         D. meeting

71. This passage tells us that Martin Luther King, Jr. ______.

A. had a difficult childhood

B. was a good musician when he was a boy

C. loved to listen to his grandfather speak

D. grew up in a relatively rich area of Atlanta

如果脉冲重复频率是10kHz，下面哪种多普勒频移可导致混迭()

A、2kHz 

B、3KHz 

C、4kHz 

D、SkHz 

E、6KHz

国际税收协定

有害生物监测的作用是（）

A、可以确保输出的产品符合输入国要求货物的原产地为有害生物非疫产地或非疫生产点、或有害生物低度流行区或非疫区的要求

B、直接杀灭有害生物

C、根据监测情况采取防治措施

D、没有什么作用

分部工程验收合格时，其包含的各分项工程的质量验收合格率至少为（）。

A.85%

B.90%

C.95%

D.100%