Identifying Towns On China Prc Military Covers - Need Help.

Hey All,
I have a few military covers from China PRC that date to the later 1990's. I've been trying to identify the towns of the sender and the receiver. I can't read the Chinese characters of the postmarks nor addresses, but I've been trying to use the postal codes. I'm not sure if any of these are correct. I've identified some towns by postal codes, but when I look up the town's name in Chinese I don't find it on the postmarks or addresses.

Cover 1
Changsha to Wuhan?



Cover 2
Changsha to ?



Cover 3
Changsha to Ya'an?



Cover 4
Changsha to Dalian?



Thanks, Will

Hi; There is this link that is interesting..
http://www.ems.com.cn/serviceguide/...cha_xun.html
For instance 410005 Hunan Changsha..
http://www.systran.fr/lp/chinese-en...translation/

Thanks,
But maybe I'm reading these covers a bit backwards. Are the postal codes for the receiver in the upper left corner boxes or is it the sender? I initially though it might be the sender, but maybe they are all going to Changsha. It would make more sense since they were all found together. It does look like the addresses are written in two parts. Top part the receiver and bottom part the sender? Soviets did this on some of their covers too. Then what are the labels on the back for?

Hopefully, I just have the sender and receiver reversed. In that case where did cover #2 come from? It's missing the written part of the address, but it does have a clear postmark.

In cover no.4 the chinese script on the front is readable by Chinese
only IMO.Really something!
Maybe the back markings are the senders registration information..?
Anyway someone who is familiar with sending and receiving mail
like this would know for sure..
Link below; some red triangle military cancels on cover:
http://www.mikewhiteuk.com/results.php?c=525