Apex domains cannot have CNAME records.
Question and response
Question
dig netease.com. NS
Answer
netease.com. 2 NS ns5.nease.net.
netease.com. 2 NS ns4.nease.net.
netease.com. 2 NS ns6.nease.net.
netease.com. 2 NS ns3.nease.net.
netease.com. 2 NS ns8.166.com.
netease.com. 2 NS ns2.166.com.
netease.com. 2 NS ns1.nease.net.
Authority
The response has no authority records.
Additional
ns1.nease.net. 2 A 42.186.168.126
ns2.166.com. 2 A 103.71.201.3
ns3.nease.net. 2 A 182.92.22.240
ns4.nease.net. 2 A 8.147.116.45
ns5.nease.net. 2 A 103.71.201.3
ns6.nease.net. 2 A 54.228.156.72
ns8.166.com. 2 A 18.182.82.158
ns8.166.com. 2 A 44.228.163.69
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0