车轴钢锻制成车轴毛坯后，要求材料的晶粒度必须达到7～8级。
参考答案：错
—________We should have been at the theatre ten minutes ago.
—Oh, dear! Let's hurry![ ]
A. Look at the time!
B. Give me a moment.
C. I'm stuck.
D. See what I mean?
呼吸衰竭最常见的诱因（）
A.呼吸系统的急性感染
B.手术创伤
C.肺水肿
D.镇静剂
E.慢性阻塞性肺气肿
