??????????????I????????????II?????????????????II?????????IIA.IIB.IIC ??????
    ??????????????????????????????????????????T1.T2.T3.T4.T5.T6????????t??????T1??????????450??t?T2??300??t?450 ??T3??200??t?300 ??T4??135??t?200??T5??100??t?135??T6??85??t?100??
    ????????????????????????????d;???????:e;???????P;???????i???????.???.?????
    ?????????????????????????????????????????????????????????????????????????????dIIBT4???????????????????????II????IIB?????????????????T4????