I try to add this:
<iframe src='http://docs.google.com/EmbedSlideshow?docid=dt8s4qc_22gwpt96ct' frameborder='0' width='410' height='342'></iframe>
into my wordpress.com but whenever I save the article the line disappear!
So I cannot embed anu google doc!
I tried also changing template but it's all the same, cannot save those iframe tags.