north college of beijing university ofchemical technology 080107021 2011 10 -201075 () 2010150020152000-5000 217oilserviceionbmw s192150003348567894s4s1. 2. 3. - 074 071201102 2009 3 28 12345 07-2 12-wto-12-3-12341 20111222011123201224(20123)5201251-200572-200184520106-2010720018press,1997.forum,1999. () 19831983198962101989200634.326.070.975.1208.3 23122.8-19.2-
