引进负压原油稳定装置中,降低稳定压力操作时,必须注意的问题是综合考虑不凝气()。
A.对入口压力的需要
B.出口压力的压降
C.对低压集气管网的压力
D.对出口压力的需要
参考答案:D
简述出口退税的概念及实行出口退税的意义。
Though he started late, Mr Guo played the piano as well as, if , Miss Liu. [ ]
A. not better than
B. not better
C. no better than
D. no better