MEI Shi - long , 1991 . Middle and Late Cambrian conodont and trilobite biostratigraphy in Wanxian, Hebei . Unpublished Ph. D thesis of Peking University.武桂春, 2003. 鲁西地区晚寒武世牙形石. 北京大学博士研究生学位论文....an unpublished PhD thesis...
The effect of root on soil respiration was observed mainly before repining stage with fluctuation.种有水稻,根系对土壤总的呼吸影响主要体现在成熟期之前,且有相互消长的现象.Cost price, nowaday value, time, fluctuation rate, un - venture gainings rate are imp...