Surprised！U.S. skeptical of Chinese swimmer's performances

So Surprised report！LONDON -- As a top American swimming official described Chinese phenom Ye Shiwen's performance as "impossible," one of the U.S. swimmers scheduled to oppose her for a medal Tuesday stopped just short of calling for an investigation. Ye set a world record in winning the women's 400-meter individual medley Saturday, swimming her final 25 meters faster than Ryan Lochte swam his final 25 meters in winning the men's 400 individual medley. On Monday, Ye set an Olympic record in a lopsided victory in the semifinals of the women's 200 IM, prompting waves of suggestions she might be using performance-enhancing substances. Caitlin Leverenz, the top U.S. swimmer in the event, said she preferred to focus her energy on swimming rather than doping. "I can't do anything about it," Leverenz said Monday. "That's USADA's and FINA's job, to do something about it. The Chinese have a history of doping in the past. I don't think people are wrong to point fingers. But I don't think that's my job." Ye, 16, denied her performances were drug-aided. "There's absolutely no problem with the doping," Ye said Monday, according to a translation provided by the official Olympic News Service. "The Chinese team has always had a firm policy about doping." The Chinese removed another 16-year-old swimmer from their team last month after a positive test for a banned substance. More than 40 Chinese swimmers tested positive for steroids in the 1990s, according to the London Times.