BEIJING — Apparently submitting to foreign human rights pressure, Beijing has freed a student activist and dropped charges against a top labor organizer in the 1989 pro-democracy protests.The government on Friday withdrew charges against Han Dongfang, a railway worker who led a worker's organization in the Tiananmen movement, according to the New China News Service. After nearly two years in jail, Mr. Han was released on bail in April because of poor health. Charges were dropped because "he actually turned himself in," the news service reported on Friday. The government released on parole Wang Youcai, a graduate student in physics at Beijing University, after he had served half of his four-year prison term. Mr. Wang was freed because "he later showed behavior of repentance," according to the news agency. Chinese officials privately acknowledge their deep concern that the United States Congress will make preferential trade status for China contingent on an improvement in its human rights record. US Secretary of State James Baker III persistently called on the government to respect basic freedoms during a Nov. 15-17 visit with Chinese leaders in Beijing. Mr. Baker voiced disappointment in the lack of progress on the issue at the end of his visit. Human rights activist John Kamm last week quoted Chinese officials as saying that other dissidents would be released before January. Mr. Kamm, a Hong Kong-based executive with Occidental Petroleum Corporation, said one of the dissidents who might be released is Wang Dan, No. 1 on a most-wanted list of student activists in the 1989 protests.