第20题: [多项选择]厌氧漂泥按照所含污泥状态包括()。 A. 正常漂泥 B. 膨胀漂泥 C. 非正常流失 D. 阶段漂泥 参考答案:A, B, C
第21题: [单项选择]{{I}} Questions 22-25 are based on the following passage. You now have 20 seconds to read the questions 22-25.{{/I}}How did Bill die A. From cancer. B. In a car accident. C. From a heart attack. D. In a plane crash. 参考答案:A