A.路由器
B.网桥
C.局域网交换机
D.集线器
参考答案:A
解析: 路由器是一种连接多个网络或网段的网络设备。它的传输延迟时间比集线器、局域网交换机和网桥要大。
根据情景选择正确的句子。
1. 当你想知道对方地址时,应说: [ ]
A. How are you?
B. Where do you live?
C. What's your address?
2. 当你想知道对方如何上学时,应说:[ ]
A. How do you go to school?
B. How are you?
C. How tall are you?
3. 当你想询问别人身高时,应说: [ ]
A. How do you do?
B. How tall are you?
C. How are you?
4. 当你想询问今天的日期时,应说:[ ]
A. What day is it today?
B. What's the date today?
C. When is it?
用频谱多普勒超声检测血流时,下列仪器调节方法中错误的是()
A.超声波入射角校正到大于60°
B.速度标尺大于被检的血流速度
C.依据血流速度大小选择高通或低通滤波
D.取样门略小于被检血管内径
E.根据被检血流速度高低选择连续波或脉冲多普勒