请选择第六个空处的正确选项Read aloud paragraphs 4 to 5 until you have learned them by heart. Then try to complete the passage from memory:Yet this stop was only part of a much larger ____ (1) for me. Josiah Henson is but one name on a long list of ______ (2) men and women who together ______ (3) the Underground Railroad, a secret web of _______ (4) and safe houses that they used to _______ (5) slaves from the American South. Between 1820 and 1860, as many as 100,000 slaves traveled the Railroad to freedom. In October 2000, President Clinton ______ (6) $16 million for the National Underground Railroad Freedom Center to _______ (7) this first great civil-rights struggle in the U.S. The center is _________ (8) to open in 2004 in Cincinnati. And it's about time. For the heroes of the Underground Railroad remain too little remembered, their ________ (9) still largely unsung. I was ________ (10) telling their stories.(仅选择本题号对应空的正确答案)