this evening i found a special way to read the subscript on MAC (i think it works for both tiger 10.4/leopard 10.5) platform... wanna share with the other ones who are using MAC like me here:
open the browser (mine is firefox for mac, but i guess safari may also work), open a new tag, drag the .ssa file icon into the new tag... done.
but the problem of this approach is that the alignment seems not so good...however, at least you can read it
sorry that i cant type chn at the moment but i will try to figure out if there is other better way later...