单项选择题
M: Only one student in my class got above 90 points in the test. How about your class? Since there are more old students in your class, I’m sure they must have done a much better job.W: About 6 or 7 of them. But there are still some students who failed.Q: What can we infer from the conversation?（）
A．The result is what she had expected.B．The test is not well designed.C．Too few students got high marks.D．Differences between students' grades are big.
多项选择题 有（）情况之一时，不得排放瓦斯。
多项选择题 在煤矿防尘技术实施中采用的减尘技术有（）。
多项选择题 煤矿个体防护用品配备要求（）。
