【亲测有效】linux ubuntu18.04 解决动态获取的dnsname无法解析某些域名的问题，保持dhcp，单独设置一个可以解析的dnsname

1，查看操作系统版本

:~$ cat /proc/version
Linux version 5.0.21-****** (gcc version 7.5.0 (Ubuntu 7.5.0-3ubuntu1~18.04)) #4 SMP Thu Dec 3 13:11:27 UTC 2020

2，查看当前的dns server信息

:~$ systemd-resolve --status
Global
         DNS Servers: 114.114.114.114
                      119.29.29.29
                      *.76.76.76
                      *.67.222.222
                      *.254.116.116
                      *.67.220.220
                      8.8.8.8
                      *.5.5.5
                      *.114.115.115
                      *.6.6.6
                      8.8.4.4
          DNSSEC NTA: 10.in-addr.arpa
                      16.172.in-addr.arpa
                      168.192.in-addr.arpa
                      17.172.in-addr.arpa
                      18.172.in-addr.arpa
                      19.172.in-addr.arpa
                      20.172.in-addr.arpa
                      21.172.in-addr.arpa
                      22.172.i