题目

— I feel so nervous about the National English Speech Competition tomorrow.    — ________.    A.That’s cool  B.Glad to hear that  C.Sounds great   D.Take it easy 答案：D把0.46g金属钠投入36g水中，溶液中水分子和钠离子的个数比是 [　　] A．100∶1B．99∶1C．90∶1D．99∶2