减压塔为什么要缩径？
参考答案：
为减少塔底渣油在高温下停留时间过长而发生分解，缩合等反应，造成塔内结焦及真空度下降，因此减压塔底要缩径.
He . Maybe there's something wrong with his throat. [ ]
A. have a backache
B. has a sore throat
C. had a headache
()根据相关规定，未经申请人申请，烟草专卖行政主管部门可以依职权向公民、法人或其他组织发放烟草专卖零售许可证。
