????:1???????:????????

2???8t????

3????????

4?????????

5?????

??6??19???? (?? ????)??????????,???????????

19??,??????3.46?(??,??)???,???????????

?????????,??????????????????????????????????????????????(????)2.13????,???,??;??????????????????????????????????????????????(??????????)0.69???????????????????,??????????,????????,????????????????????????????,????????;????????????????????????0.64????,???,????????

??,???4.43????,?????

??????????????,???????????????????????????????????4.43?????????????????,?????????????????????????????????????????7??????????????,???????????????????,??????????????????????,???,???(?) ????????:???