液氮调试方案应明确规定（）程序。
A、管道压力试验
B、管道冲洗吹扫
C、紧急情况处理
D、加气操作
参考答案：C
— Sorry, wrong number.
— ____.[ ]
A. That's right
B. You're right
C. All right
D. That's all right
_________ countries having great difficulties in economy right now need most of all is financial
aid rather than blaming.
A. What
B. When
C. That
D. Whether
