Grains markets closed mixed in quiet trade with corn unch to off a penny, beans down 5-9 cents, and wheat mixed with KC HRW firmer and Mpls and Chi softer. Temperatures were cold enough over the weekend to damage jointing and heading winter wheat in parts of TX, OK, and central Ks and forecasted lows dip well below freezing again Thursday morning. Additionally, USDA FAS announced HRW export sales to China on Friday and again today—for a total of 285,000 tonnes. Not too shabby…