沟火
参考答案:在窑的两旁及窑尾等边缘部分,往往由于燃烧不到而温度不够,窑工必须将火引伸过去,谓之“沟火”,意即沟通火焰。一般采用泼水的办法把火焰引过去,是很见成效的沟火方法。
—You know that you were driving at 100 kilometers per hour, don’t you?
—No, officer, I _____ have been. This car can’t do more than 80.
A.mustn’t
B.shouldn’t
C.may not
D.couldn’t
检测限是指一定分析测试手段在一定实验条件下所能检出的()。