血常规检查发现患儿红细胞计数和血红蛋白明显增多,患儿可能患有()。
A.房间隔缺损
B.室间隔缺损
C.动脉导管未闭
D.法洛四联症
E.肺动脉狭窄
参考答案:D
— Where did you find Mr. Smith?
— It was in the library _____ we often went to read. [ ]
A. that
B. when
C. what
D. where
OSI七层协议中,传输层传送数据的单位为()
A.比特
B.帧
C.分组
D.信息