(Beaverton, OR)  --  Voters in Beaverton will be asked to decide in May on whether to approve a 680-million-dollar school bond issue.  Among the purposes for the proposed bond are building three new schools, rebuilding and renovating others, effecting school-building repairs, and adding new technology to schools.  The Beaverton School Board voted last night to place the measure on the May ballot.  If the bond passes, Beaverton property owners would pay two-dollars-eleven-cents per thousand dollars of assessed home value.