听力原文： Hundreds of people have been killed in a stampede during a Shiite religious ceremony in Baghdad. Iraqi officials say at least 640 have died and the figure may rise. The disaster comes as Iraqis are registering to vote on the country's proposed new constitution, an issue which has sharply divided the ShiRe and Sunni communities. From Baghdad John Brain reports:
'The stampede began as up to a million Shiites were making their way towards a holy shrine in the north of the city. Rumors circulated that a suicide bomber was amongst the crowds. In the resulting panic hundreds of worshipers were crushed to death as they tried to escape a crosser bridge over the river Tigris. The bridge's iron railings then collapsed, throwing hundreds more people over the side. Tensions had already been high after several mortars were fired towards the shrine early in the day, killing 16 worshipers, an attack clearly aimed at fermenting sectarian divisions. Iraq's Prime Minister Ibrahim al-Jaafari has declared three days of national mourning.'
How many people have died in the disaster?
A．Less than 600.
B．Less than 640.
C．614 or so.
D．More than 640.