丙烯纯度低调节
参考答案：
降低精丙烯塔底温度；调节热旁路，适当提高塔压力；调节回流，增大回流量；降低精丙烯顶馏出量，搞好物料平衡。
A. give a friend a rideB. adopt a new hobbyC. feel less out of controlD. learn a new set of skillsE. need each other to surviveF. take some time to exerciseG. weigh down hard on one’s family life
When looking for a new job in hard times, one may have to ______.
紧急停蒸气时蒸馏加碱必须停止。
