[R] How to strip one term from a data.frame? + How to write long line in script?

[Guojun Zhu]

I need to run a regression with 14 normal variables
and 20 dummy variables.  All the data is in a huge
data.frame  df.  But there is some extra intermediate
item in the same data.frame too.  It will be nice I
can strip off those terms and run lm().  Also, is
there a simple way to write the formula, for example,
just specify the y term, all other term in data.frame
should be x_i.  Or is there some kind of automatically
way to build it?  like use ls(df) couple with some
other functions?  


If I have to write it in the brute force way, I will
need to write a real long line in script.  I am in
windows.  I found the script does not work with a long
line.  It will not work either if I break it into a
few lines.  How to get rid of that? thanks.