Apex domains cannot have CNAME records.
Question and response
Question
dig sci.uz. NS
Answer
sci.uz. 5 NS ns01.uzsci.net.
sci.uz. 5 NS ns08.uzsci.net.
Authority
The response has no authority records.
Additional
ns01.uzsci.net. 5 A 83.69.129.4
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0