休克（ ）
A．肺性发绀
B．心性混合发绀
C．淤血性发绀
D．缺血性发绀
E．混合性发绀
参考答案：D
— have you stayed in Shanghai?
— For about seven days.
A. How soon B. How long C. How often
开机前认真检査内喷雾泵（）是否正常。
A.运行声音
B.温度
C.运转速度
D.震动
