[O] Change font size temporarily for pdf export

[Shiyuan]

Hi,
   When a src code block is exported to latex-pdf, the src lines sometimes
are too long to fit in a pdf line. One easy way to handle this problem I
can think of is to temporarily change font size. What is the best way to do
that in org model?  Say that if I have two src blocks, I want the first
code block to be typeset in scriptsize but the second block typeset in
normalsize .

#+BEGIN_SRC R
print("This block in scriptsize")
......
#+END

#+BEGIN_SRC R
print("This block back to normalsize")
......
#+END

Thanks.