反应器开车时,硅烷从反应器()加入,其进料与()成比例控制,反应器运行稳定后,硅烷从反应器()加入,其进料的与()成比例控制。
参考答案:顶部;三乙基铝进料;主进料口;催化剂进料
— Michael was late for Mr. Smith's oral class this morning.
— _______? As far as I know, he never came late to class.[ ]
A. How come
B. So what
C. Why not
D. Guess what
零售,含脱脂奶粉、豆粉、酵母、维生素等添加物的婴幼儿食用奶粉