[R-sig-Geo] delete region from shapefile / map only certain regions

[stefan lhachimi]

Hello,
I have two qeustions about shape files:

First, I have a shp.file for all counties in Germany. Funnily enough,
two counties are just lakes for which
    I do not have covariates. Is there a possibilty delete them, so
they don't show on the map and do not affect my analysis.


Second, is it possible just to plot parts of the map, given some
condition (say, part of a state or a larger region)?

I hope these question are not too trivial, but I couldn't find
anything adequate in the mailing list.
Happy new Year,
Stefan