The Sensex at the Bombay Stock Exchange dropped 220 points, or 1.2 percent, to close below the key 19,000 level, at 18,858, today. Earlier during the session, however, the Sensex had climbed to a nine-week high of 19,132. The Nifty at the National Stock Exchange lost 68 points, or 1.2 percent, to 5,661.Stock markets in Japan, China, Hong Kong, and Singapore rose between 0.1 percent and 0.9 percent.