题目

—Why weren't you at the meeting?—I________ for a long distance call from my sister in America. A . was waited B . was waiting C . has waited D . have been waiting 答案：B已知y=loga(2-ax)在[0，1]上是x的减函数，则a的取值范围是(　) A．(0，1)　　　　　　　　　　　 B．(1，2) C．(0，2)　　　　　　　　　　　 D．[2，+∞