若精馏塔某理论板上气相露点温度为t1，液相泡点温度为t2，则t1与t2的关系为（）。
A、t1>t2
B、t12
C、t1=t2
D、无法判断
参考答案：C
从技术经济角度看，小机组也应采用蒸汽冷却器和疏水冷却器。（）
A．Because she could not sleep well at night.
B．Because she hoped to earn more money.
C．Because she could not find a daytime job.
D．Because she needed a change and a lighter job.
