CHICAGO (AP) _ Grain futures were mostly lower in early trading Wednesday on the Chicago Board of Trade. Dec. corn fell by 0.25 cent at $4.62 a bushel. Dec. wheat was unchanged at $6.43 a bushel. Dec. oats gained 0.75 cent at $3.85 a bushel. Nov. soybeans fell by 0.75 cent at $12.47 a bushel....