题目

22. ---Mike! Don't tell me you are the guy I am waiting for? It can't be true! ---Yes, I am the guy. ---What a bummer, _________.    A.You set me up.   B. I don't know    C.What if   D.You are kidding! 答案：A按下图装置持续通入X气体，并在管口P处点燃，实验结果使澄清的石灰水变浑浊．则X、Y可以是 [　　] A．B．CO和 C．CO和CuOD．