21. _The testing technology has become extremely sophisticated and can catch more players who use masking agents . 22. Masking agents also are uncovered and explored.23. He also criticized four Chinese swimmers who tested positive to a banned masking agent during the competition. 24. Diuretics are banned because they can be used as masking agents for other drugs, including anabolic steroids. 25. The substance was probenecid, a medicine for the kidney and also a masking agent for anabolic steroids. 26. More than 350 athletes have or will be tested for banned performance-enhancers, including steroids and masking agents . 27. Much of sport remained a competition among chemists, with hot drugs and masking agents lurking in many athletes'systems. 28. His career suffered a major setback in 2002 when he tested positive for the banned masking agent probenecid. 29. The IOC lists bromantan as both a stimulant and a masking agent , while clenbuterol is a steroid-related drug. 30. -- Diuretics and other masking agents
