两种硫酸盐按一定比例混合后共熔，可制得化合物X，X溶于水能电离出K+、Cr3+、2SO4，若将2.83gX中的Cr3+，全部氧化为2Cr2O7

后，溶液中的2Cr2O7可和过量KI溶液反应，得到3.81gI2，反应的离子方程为若向溶有2.83gX的溶液中，加入过量的BaCl2溶液，可得到4.66g白色沉淀.由此可推出X的化学式为()

()1.Couldyouhelpme，please?A.OK.

()2.Thanksalot.B.You'rewelcome.

()3.Let'sputthebooksinthebox.C.It'sMonday.

()4.Canyoucarryit?D.No，it'sfull.

()5.Who'sondutytoday?E.lam.

()6.Isitempty?F.No，it'slight.

()7.Whatdayisittoday?G.Certainly.

()8.Isthatbagheavy?H.No.LiLeiisn'there..

()9.Areweallheretoday?I.No，thanks.

()10.Letmehelpyou.J.Yes，Ican.

It'stime____playgames.

()Pleasegivemetwobottlesof_______.

近几年在洞庭湖地区实施“退田还湖”工程，已出现的变化是()