题目

下列物质的水溶液在空气中小心加热蒸干,能得到较纯净的原溶质的是 A.CuSO4             B.FeSO4         C.NaHCO3        D.FeCl3 答案：A—May I speak to your manager Mr. Williams at five o'clock tonight? —I'm sorry. Mr. Williams　　  to a party long before then.     A. will have gone    B. had gone　　 C. would have gone　　  D has gone