一个人对某一事物采取积极态度趋向的主要根源是()
A.动机B.兴趣C.需要D.利益

Passage One Questions 21 to 25 are based on the following passage. Him Mark Lai(麦礼谦) died on May 21,2009. Born in San Francisco in 1925 and known as the "Dean of Chinese American History," he was professionally trained as a mechanical engineer with no training in history. Yet he co-taught the first college course on Chinese American history with Philip Choy at San Francisco State University in 1969--the first university-level course on Chinese American history-and also taught the same course at UC Berkeley in the 1970s. Lai published more than 100 essays and 10 books in English and Chinese, several of which are considered important resources in Chinese American history. His key works include A History of the Chinese in California, co-edited with Thomas Chinn and Philip Choy, and Outlines: History of the Chinese in America, also written with Choy, who co-taught the 1969 class. His most well-known work is Island: Poetry and History of Chinese Immigrants on Angel Island, 1910-1940, which he co-authored with Judy Yung and Genny Lim. These three translated the Chinese poetry found on the walls of the Angel Island Immigration Station. They also collected oral histories of people who suffered a lot on Angel Island because of the 1882 Chinese Exclusion Act. Their resulting manuscript was published by University of Washington Press in 1991. In 1991 Him Mark Lai and Albert Cheng created "In Search of Roots Program" through a partnership with the Chinese Historical Society of America, Chinese Culture Foundation, and the Overseas Chinese Affairs Office from Guangdong Province, China This year-long program trains a dozen Chinese American youths how to research their family history through National Archives and Records Administration documents and oral history. "He was one of the most important historians of Chinese America," said Russell. c Leong, editor of UCLA's Amerasia Journal, who called Lai a historian of the people.

21. The second paragraph focuses on Him Mark Lai's achievement as________.