Submitted on: 14 December 2000.
Revised on: 10 January 2001.
Accepted on: 28 January 2001.
___________________Afghanistan---EDINBURGH UNIV PRESS
http://reply.papertrans.cn/1/9/867/867-32.png
http://reply.papertrans.cn/1/9/867/867-33.png
http://reply.papertrans.cn/1/9/867/867-34.png
http://reply.papertrans.cn/1/9/867/867-35.png
Submitted on: 20 May 2004.
Revised on: 17 August 2004.
Accepted on: 22 September 2004.
___________________Afghanistan---EDINBURGH UNIV PRESS