题目

 —I’m sorry to have kept you waiting.  —_____ .I’ve just arrived here myself. A.It doesn’t matter  B. Promise  C .I’ll see to that  D. Here it is 答案：A16．下列物质属于纯净物的是（　　）A．食醋B．矿泉水C．碘酒D．四氧化三铁