Apex domains cannot have CNAME records.
Question and response
Question
dig resource.edu.cn. NS
Answer
resource.edu.cn. 1 NS dns2.resource.edu.cn.
resource.edu.cn. 1 NS dns1.resource.edu.cn.
Authority
The response has no authority records.
Additional
dns1.resource.edu.cn. 1 A 202.205.109.1
dns2.resource.edu.cn. 1 A 202.205.109.10
dns1.resource.edu.cn. 1 AAAA 2001:da8:20d:22:0:0:0:8
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0