Apex domains cannot have CNAME records.
Question and response
Question
dig china-entercom.net. NS
Answer
china-entercom.net. 5 NS dns2.cibonet.com.
china-entercom.net. 5 NS dns1.cibonet.com.
Authority
The response has no authority records.
Additional
dns1.cibonet.com. 5 A 210.5.1.234
dns2.cibonet.com. 5 A 218.97.46.222
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0