题目

The________expression on his face suggested that he was________at the extraordinary beauty of the picture. A . astonished; astonished B . astonishing; astonished C . astonished; astonishing D . astonishing; astonishing 答案：A等浓度的下列稀溶液：①乙酸、②苯酚、③碳酸、④乙醇，它们的pH由小到大排列正确的是（　　）A．④②③①B．③①②④C．①②③④D．①③②④