Apex domains cannot have CNAME records.
Question and response
Question
dig shumochina.com. NS
Answer
shumochina.com. 5 NS ns-225.awsdns-28.com.
shumochina.com. 5 NS ns-637.awsdns-15.net.
shumochina.com. 5 NS ns-609.awsdns-12.net.
shumochina.com. 5 NS ns-1600.awsdns-08.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0