Attendants working for U.S. slot machine maker Bally Technologies learn a poker game before introducing it to visitors at Gaming Expo Asia in Macau May 22, 2012. Gaming executives and industry players gathering for a convention in Macau on Tuesday may have to finally confront what they have been predicting for the past two years -- a sharp slowing of growth in the world's hottest gambling market. REUTERS/Bobby Yip (CHINA - Tags: BUSINESS SOCIETY)