摘自：http://www.flash-db.com/Tutorials/lclasses/

The three classes implement a queue, so successive calls are dispatched in order, one after the other. This could be no the intention in some situations, so don't use this class if you want to load all at once (using multiple LoadVars object or Pending Calls when using web services or Remoting) In some cases, multiple calls could competes for bandwidth when using large results (some web services returns huge large XML documents or Remoting services large recordsets) so I usually try to resolve in order. ……