诊断性腹腔穿刺和腹腔灌洗术，在诊断腹部创伤时，其阳性率可达
A．90％
B．80％
C．70％
D．60％
E．50％
参考答案：A
解析：诊断性腹腔穿刺和腹腔灌洗术在诊断腹部创伤时是比较理想的辅助性诊断措施，阳性率可达90％以上，故对于判断腹腔内脏器有无创伤和哪一类脏器创伤有很大帮助。通过检查灌洗液中含有的血液、胆汁、胃肠内容物、尿液、红细胞计数、白细胞计数、淀粉酶、细菌等协助诊断。
| 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 fewer people know much about King’s childhood. M. L., as he was called, was born in 1929 in Atlanta, Georgia, at the home of his maternal grandfather. M.L.’s grandfather, the Reverend A. D. Williams, purchased their home on Auburn Avenue in 1909, 20 years before M. L. was born. The Reverend Williams, an eloquent speaker, played an important role in the community since 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. M.L. grew up in this atmosphere, with his home being used as a community gathering place, and was no doubt influenced by it. M. L.’s childhood was not especially eventful. 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 neighborhood. The neighborhood was not poor, however. Auburn Avenue was the main artery through a prosperous neighborhood that had come to symbolize achievement for Atlanta’s black people. It was an 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, the district thrived. Dr. King never forgot the community spirit he had known as a child, nor did he forget the racial prejudice that was a seemingly insurmountable barrier that kept black Atlantans from mingling with whites. |
The word "it" underlined in Paragraph 2 refers to ______.
A．achievement
B．neighborhood
C．segregation
D．services