CHICAGO (AP) _ Grain futures were mostly lower Monday on the Chicago Board of Trade. Dec. corn rose by 0.5 cent at $4.55 a bushel. Dec. wheat fell by 9.5 cents at $6.16 a bushel. Dec. oats lost 11 cents at $3.61 a bushel. Nov. soybeans lost 7.75 cents at $12.42 a bushel. Beef was...