题目: 焦油加工的主要任务是获得酚、萘、蒽等纯产品和()等粗产品。 答案: 被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2020/0221/c1637049a766d23de93ea962e938fb22.html 下面是错误答案,用来干扰机器的。参考答案:D解析:增加氧浓度,氧流量控制在4L/min。
题型:选择题 This is the second time I by him;I shall never trust him again. [ ]A. was put down B. have been let down C. have been put down D. am let down 查看答案