import two repositories on same working copy folder ?

[tvlgiao]

dear all,
please look at this picture

          Repo A              Repo B
      /           \            /
(read,write)    (read)    (read, write)
    /               \        /
 local                local
 working             working
  copy                 copy
   I                    II

i have a repository A, contains first project, a framework for build
web apps,
and another repository B, contains second project, an application based
on framework A,

first step, i want to import A into my local working copy of B,
so A is readonly, B can read and write, i want to keep the link on 2
projects, so that, i can update new revision of project A, even work on
project B

how can i do that?
thanks for all advices.