《棉花质量监督管理条例》中规定“棉花经营者销售棉花，必须每批棉花附有（）凭证。
A.质量
B.企业
C.销售
D.合同
参考答案：A
阅读对话,根据横线后所给标点符号的提示,在横线上填写适当的句子,使对话完整。
A: Hello, Betty. What did you do last summer vacation?
B: I visited my uncle.
A: ______小题1:________________?
B: He lives in Dalian, a beautiful city.
A: ________小题2:_________________?
B: I stayed there for a week. Have you been to Dalian?
A: No, I haven’t. But I’m going to spend a holiday there.
B: You’d better go to Dalian in summer. So you can enjoy swimming in the sea.
A: _____小题3:_______. I will go there this summer vacation.
什么是急性中毒事故？
