下列甲状腺癌和腺瘤的超声鉴别点中最主要的是()。
A.肿块有否囊性变
B.肿块血供是否丰富
C.肿块的回声强弱
D.肿块的边界是否整齐
E.肿块周边血流有否绕行
参考答案:D
航空仪表按工作原理分为()类.
A、测量仪表、计算仪表、调节仪表
B、飞行仪表、发动机仪表、其他设备仪表
C、大气数据仪表、姿态仪表、舵向仪表
D、膜盒仪表、陀螺仪表、指引仪表
Premier Zhou (周 * * ) _____ for many years, but he still lives in the hearts of the Chinese people. [ ]
A. died
B. had died
C. has been died
D. has been dead