President Bush and his advisers went over final preparations today for a U.S.-Soviet summit that a top aide said will tackle ``bare bone essentials'' rather than tallying up agreements to sign. Bush and Soviet President Mikhail S. Gorbachev will likely issue a statement of progress on nuclear arms reductio as sign various cultural and economic agreements when they meet this week, said a senior admin talks, as wellnistration official who briefed White House reporters. But the official, speaking on condition of anonymity, cast doubt on prospects for a U.S.-Soviet trade agreement before Gorbachev leaves. ``We're in a rather uncertain state about what exactly will happen on the trade agreement,'' the official said, citing U.S. unhappiness over Soviet actions in Lithuania and the Soviets' failure to enact legislation allowing free emigration. Still, the official said, ``This is not a summit devoted to the celebration of agreements that we can sign. It is a summit designed to do the hard work of trying to overcome the remaining obstacles that stand in the way of transforming East-West relations.'' ``We are now dow: Education Program.