肝经郁火犯胃而致呕吐的呕吐物特点是（）。
A.呕吐物清稀
B.呕吐物秽浊酸臭
C.伴暗红色血
D.伴食物残渣
E.呕吐黄绿苦水
参考答案：B
Jack wasn ' t saying anything but the teacher smiled at him _____ he had done something very clever. [ ]
A. as if
B. in case
C. while
D. though
超水压试验时可以参与与试验的设备有（）。
A、安全门；
B、省煤器；
C、过热器；
D、水位计。
