CHICAGO (AP) _ Grain futures were mostly lower in early trading Monday on the Chicago Board of Trade. Dec. corn was off 0.25 cent at $4.97 a bushel. Dec. wheat was unchanged at $6.83 a bushel. Dec. oats gained 0.25 cent at $4.08 a bushel. Nov. soybeans was off 0.25 cent at $12.78 a bushel....