分馏塔冲塔的原因有（）
A、塔底液位过高
B、塔顶压力突增
C、塔顶回流中断
D、进料组分变化，组分过轻
参考答案：A, C, D
What a beautiful dress in the window!（）
A.I have no idea about it.
B.Yes, really. If I had the money, I‘d buy it.
C.You can‘t wear it.
D.There‘s no money to buy it
带电作业对使用的绝缘工具的存放、运输、使用有哪些要求？
