题目

下列有关实验操作、现象、解释和结论都正确的是( ) 选项操作现象解释、结论A用玻璃棒蘸取浓氨水点到干燥红色石蕊试纸上试纸变蓝色浓氨水呈碱性B向饱和Na2CO3溶液中通入足量CO2溶液变浑浊析出了Na2CO3晶体C向蔗糖中加入浓硫酸并搅拌蔗糖变黑，体积膨胀反应中浓硫酸只体现脱水性D过量的Fe粉与氯气充分反应后，向反应后的混合物中加水，取上层清液滴入KSCN溶液溶液不变红色氯气将Fe氧化为Fe2＋ A. A B. B C. C D. DThe Nobel Committee praised the “change in the international climate” that Barack Obama had brought, ________ his precious goal of ridding the world of nuclear weapons．A.along withB.in case ofC.except forD.in spite of