常见于分泌性中耳炎耳咽鼓管功能障碍的鼓室压力图为()。
A.A型
B.As型
C.Ad型
D.B型
E.C型
参考答案:E
Hardly had she walked out of the woods ___ she heard the strange scream coming from behind a tree.
A.than
B.until
C.since
D.when
当锅炉超过预先调整的()时,安全阀动作,排出一部分蒸气使锅炉降压并警告司机司炉。