| 1 | LIN Yanghui; XU ChuanquanInspection Department; Hospital of Pingnan County; Fujian; 352300; | |
| 2 | The study is carried out on-the-spot survey amd research of Pingnan county. | |
| 3 | To investigate some children aged 1 to 2 years old by PPS methods during 2001-2004 in Nanping county. |