下列传输方式中属于基带传输的是（ ）。
PSK编码传输：相移键控(PSK)是一种数字调制方案，通过改变或调制参考信号(载波)的相位来传输数据。
PCM编码传输：脉冲编码调制(PCM)，对连续变化的模拟信号进行抽样、量化和编码产生的，称为PCM，即脉冲编码调制。
QAM编码传输：QAM调制叫做正交幅度调制，是由两个正交载波的多电平振幅键控信号叠加而成的，也可看为联合控制正弦载波的幅度及相位的数字调制信号。
The Internet of（ 1）（IoT） describes physical objects that are embedded with Sensor，processing abilities，softwares，and other technologies that connect with other devices and systems over the （ 2） or other communication and exchange data networks .Over the past few years, IoT has become one of the most important technologies of the （ 3 ） centuryWe can connect objects to the Internet via embedded devices. By means of（ 4） computing, the cloud, big data, and mobile technologies, physical things can share and collect data with minimal human intervention. Traditional fields of embedded systems，wireless （ 5） networks （WSNs），control systems，automation, independently and collectively enable IoT.回答5处
The Internet of（ 1）（IoT） describes physical objects that are embedded with Sensor，processing abilities，softwares，and other technologies that connect with other devices and systems over the （ 2） or other communication and exchange data networks .Over the past few years, IoT has become one of the most important technologies of the （ 3 ） centuryWe can connect objects to the Internet via embedded devices. By means of（ 4） computing, the cloud, big data, and mobile technologies, physical things can share and collect data with minimal human intervention. Traditional fields of embedded systems，wireless （ 5） networks （WSNs），control systems，automation, independently and collectively enable IoT.回答4处
The Internet of（ 1）（IoT） describes physical objects that are embedded with Sensor，processing abilities，softwares，and other technologies that connect with other devices and systems over the （ 2） or other communication and exchange data networks .Over the past few years, IoT has become one of the most important technologies of the （ 3 ） centuryWe can connect objects to the Internet via embedded devices. By means of（ 4） computing, the cloud, big data, and mobile technologies, physical things can share and collect data with minimal human intervention. Traditional fields of embedded systems，wireless （ 5） networks （WSNs），control systems，automation, independently and collectively enable IoT.回答3处
The Internet of（ 1）（IoT） describes physical objects that are embedded with Sensor，processing abilities，softwares，and other technologies that connect with other devices and systems over the （ 2） or other communication and exchange data networks .Over the past few years, IoT has become one of the most important technologies of the （ 3 ） centuryWe can connect objects to the Internet via embedded devices. By means of（ 4） computing, the cloud, big data, and mobile technologies, physical things can share and collect data with minimal human intervention. Traditional fields of embedded systems，wireless （ 5） networks （WSNs），control systems，automation, independently and collectively enable IoT.回答2处
The Internet of（ 1）（IoT） describes physical objects that are embedded with Sensor，processing abilities，softwares，and other technologies that connect with other devices and systems over the （ 2） or other communication and exchange data networks .Over the past few years, IoT has become one of the most important technologies of the （ 3 ） centuryWe can connect objects to the Internet via embedded devices. By means of（ 4） computing, the cloud, big data, and mobile technologies, physical things can share and collect data with minimal human intervention. Traditional fields of embedded systems，wireless （ 5） networks （WSNs），control systems，automation, independently and collectively enable IoT.回答1处
管理员要检查本地主机TCP/IP协议是否能够正常工作，应使用下面（ ）命令。
在Windows系统中，可以在“运行”对话框中使用（ ）打开命令行窗口。
在Windows 系统中，要持续ping某主机，应使用（ ）选项。
在Linux系统中，管理员在DHCP服务器的配置文件中添加了下面一段代码:subnet 192.168.20.0 netmask 255.255.255.0{range 192 .168 .20 .10 192 .168 .20.50;option domain-name-server ns1 .internal.example.comoption routers 192 .168 .20.254;option broadcast-address 192.168.20.255;default-lease-time 1200;max-lease-time 360000;}当该DHCP服务器启动后，下面分配给客户端的IP地址中，正确的是（ ）.
在Linux系统中，通常使用（ ）为用户提供FTP服务，其配置信息存放在（回答此处）目录中。
