(Undated)  --  Defending College World Series champion Oregon State is scheduled to open a four-game series today with Nebraska in Surprise, Arizona.  The game, however, is in danger of being postponed with an 80 percent chance of rain today in Phoenix.  The Beavers are 4-and-0,  sweeping the Sanderson Ford College Baseball Classic at Surprise Stadium.  The Oregon Ducks will play Saint Mary's tomorrow in their home opener in Eugene.  It will be the opener of a four-game series, which includes a Saturday doubleheader.  Oregon lost two-of-three at number-eight Texas Tech last weekend to start the season.