How to cache the partial alone?

Suppose the partial: _form.rhtml, it includes lots of data and has a
fixed layout and is reused for over 5 views,for every time it is
rendered for a long time,therefore to cache it is a useful way to
improve the throughoutput. However, the partial _form.rhtml. Can this
whole partial file alone be cached?
Another question: the web application is a multi language version, other
language is translated by gettext using <%= _("") %>, therefore,if an
English version of _form.rhtml could be cached, how other language
version of _form.rhtml was cached?Very grateful!

Fred