Wheat:  Net sales of 312,900 metric tons for 2019/2020 were down 56 percent from the previous week and 46 percent from the prior 4-week average.   Corn:  Net sales of 531,400 metric tons for 2019/2020 were down 15 percent from the previous week and 43 percent from the prior 4-week average.  Soybeans:  Net sales of 330,300 MT for 2019/2020--a marketing-year low--were down 55 percent from the previous week and 66 percent from the prior 4-week average.   Soybean Cake and Meal:    Net sales of 94,700 MT for 2019/2020 were down 31 percent from the previous week and 41 percent from the prior 4-week average.   Soybean Oil:  Net sales reductions of 1,900 MT for 2019/2020 resulting...