A:to be exhibited
B:being exhibited
C:are being exhibited
D:have been exhibited
— Yes, _______.
①80℃时,甲物质的溶解度是____;
②t2℃时,把甲、乙、丙三种物质的饱和溶液降温到t1℃,溶质质量分数不变的是____;
③若要让乙物质从它的饱和溶液中全部结晶析出,应采取的方法是____.