颈部血管超声常用探头为()
A.线阵式探头
B.凸阵式探头
C.脉冲探头
D.1MHz探头
E.笔式探头
参考答案：A, B
计算机采用了“存储数据“的工作原理。这一原理是1946年的由冯﹒诺依曼提出的。
—What did your kids do weekends?
—They watched TV Saturday afternoon. [ ]
A. on / on
B. on / in
C. in / in
D. in / on
