扁桃体周脓肿穿刺抽脓时,因刺入过深,最容易导致的并发症是()
A.伤及颈椎横突
B.脓液抽出困难
C.咽旁隙感染
D.刺入扁桃体内
E.误伤咽旁大血管
参考答案:E
We should learn from those ____ are always ready to help others. [ ]
A. who
B. whom
C. they
D. that
无线通信中H2A意思是()
A.等幅电报
B.载波单边带电话
C.独立边带抑制载波电话
D.全载波单边带电报