Apex domains cannot have CNAME records.
Question and response
Question
dig fetec.org.tw. NS
Answer
fetec.org.tw. 1 NS dns01.fetnet.net.
fetec.org.tw. 1 NS dns02.fetnet.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0