尿素车间有哪几个岗位（）
A、泵房
B、转化
C、压缩
D、中控
参考答案：A, C, D
— Which is more useful, English or Chinese?
— I think ______ them are useful. [ ]
A. either of
B. none of
C. both of
什么是饱和温度？压力和饱和温度的关系如何？
