眼球后血肿可引起（）
A.眼睑淤血
B.眼球突出
C.球结膜下出血
D.眼球运动障碍
E.眼球搏动
参考答案：A, B, C, D
During a morning assessment, the nurse percusses tympany. The nurse understands that tympany is a loud, high-pitched, moderately long sound with a drumlike, musical quality that’s most commonly heard over the（）
A. heart.
B. liver.
C. pancreas.
D. stomach.
只有当晶闸管同时承受正向阳极电压和正向门极电压时，晶闸管才可以导通。
