as described in
Ubuntu下Firefox打开mht格式文件
http://www.javaeye.com/wiki/topic/348796
go to :
UnMHT for Firefox
http://www.unmht.org/unmht/en_previous.html
select the latest version to install, current is
Ver.5.2.11 | unmht-5.2.11.xpi | (316,629 bytes) | [2009/07/25] |
after install it, restart firefox, then you can use it to open the .mht file. ^_^