Rising for the third straight day, the Sensex at the Bombay Stock Exchange gained 34 points to close at a fresh 28-month high of 20,247, today, on continued hopes of a rate cut. The Nifty at the National Stock Exchange rose 23 points, to 6,170.Stock markets in China, Hong Kong, South Korea and Singapore climbed between 0.2 percent and 1.2 percent.