BEIJING, Oct. 1 (Xinhua) -- Major tourist sites in Olympic host Beijing welcomed 300,000 tourists on Monday, the first day of the weeklong National Day holiday, according to the capital's holiday office.     Due to a drizzle in early morning on Monday, the capital's influx of tourists slightly dropped compared with the same day last year, the office said.     The average rental rate of the city's luxury restaurants and other hotels stood at about 60 percent on Monday.     About one million pots of flowers were used in major parks to form 25 theme parterres featuring the Olympic Games and festive atmosphere, according to an official with the Beijing park administration center.     "The decorations are a rehearsal of the park appearance arrangement for the 2008 Beijing Olympic Games," said the official. The event is scheduled to take place from Aug. 8 to 24 next year.