给定关系模式R＜U，F＞，其中：属性集U＝{A，B，C，D，E，G}，函数依赖集F＝{A→BC，C→D，AE→G}。因为（AE）F＋＝U，且满足最小性，所以其为R的候选码；若将R分解为如下两个关系模式（ ），则分解后的关系模式保持函数依赖。
（1）本题第一空是对候选关键字的考查。
可以利用图示法分析，入度为0的属性集合为{A，E}通过该集合出发，可以遍历全图。
（2）本题第二空是对模式分解的考查。
A项：分解R1（A，B，C）和R2（D，E，G），可得F1＝{A→BC}，F2为空，所以F＝F1＋F2＝{A→BC}，丢失函数依赖C→D，AE→G，所以分解后的关系模式不保持函数依赖。
B项：分解R1（B，C，D，E）和R2（A，E，G），可得F1＝{C→D}，F2＝{AE→G}，所以F＝F1＋F2＝{C→D，AE→G}，丢失函数依赖A→BC，所以分解后的关系模式不保持函数依赖。
C项：分解R1（B，C，D）和R2（A，E，G），可得F1＝{C→D}，F2＝{AE→G}，所以F＝F1＋F2＝{C→D，AE→G}，丢失函数依赖A→BC，所以分解后的关系模式不保持函数依赖。
D项：分解R1（A，B，C，D）和R2（A，E，G），可得F1＝{A→BC，C→D}，F2＝{AE→G}，所以F＝F1＋F2＝{A→BC，C→D，AE→G}，没有丢失函数依赖，所以分解后的关系模式保持函数依赖。
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。
