?????

??????????????????????????5059?7.4?6069?5.8?7079?3.3????????????10???????
??????60???????????????30????20?????120??50???30?
?????12???10?5???????60??25??20????????????????????25%???10?12?www.elifeway.com

????????????????? 1. ????????????????????????????????????23
2.? ???????30???????????????????;?...

?????????, ????,????????????????
???????????, ?????????, ???????, ????, ???????
???????????????????????????????????????????
???????????????????????????????????????????????5060????????????????????????????????????????????
??????????????????^??????????????????????????????????????
???????????.??????.???...

?????????????

20?????????

2030???????????????

3040????????????????????

4050????????

50?????????????????????
?20?
> 1
>????????
>
> 2
>????????????20??3?????
>
> 3
>??2?????
>
> 4
>??????????
>
> 5
>?????????
>
> 6
>??????...

????

???????50%???25%?25%????????????

???n???
????????????????

?????????

??f?????????

????????????

?????????????????

???????????98%??12~24?

??????????????????????????????????????
????? http://www.jiaoyuda.com ? ???? http://www.zazhijie.cn? http://www.ggykf.com? http://www.nanbeiqiao.com?? http://www.91qikan.comwww.fanwen.com
????????? http://www.cnki.net??? http://www.qikan.com?? http://www.wanfangdata.com? http://www.interpapers.com/k...